Polycarbonate resin composition

ABSTRACT

A polycarbonate resin composition comprising, 100 mass parts of (A1) a polycarbonate resin that contains a polycarbonate resin having a structural unit of the following general formula (1) and (A2) a polycarbonate resin having a structural unit of the general formula (2) in a mass ratio (A1)/(A2) of 100/0 to 10/90; 3 to 20 mass parts of a phosphorus flame retardant (B); 2 to 20 mass parts of a silicone flame retardant (C); and 3 to 100 mass parts of an inorganic filler (D), wherein the phosphorus flame retardant (B) is a phosphazene compound and/or a condensed phosphate ester,[C1]

TECHNICAL FIELD

The present invention relates to a polycarbonate resin composition andmore particularly relates to a polycarbonate resin composition thatachieves an excellent low heat release performance and an excellent lowsmoke generation performance.

BACKGROUND ART

Resin materials have in recent years begun to be used for variousinterior members for the vehicles typical of, for example, railways, andpolycarbonate resins have already entered into use for interior membersin, e.g., railway vehicles and aircraft.

Application as a railway vehicle material requires compliance with theflame retardancy standards for railway vehicles set by the particularcountry or a particular governmental agency. Moreover, more rigorousfire protection standards than in the past have come to be required ofvehicle materials based on considerations of enhancing safety. Inparticular, the newly issued EN 45545-2 European Railway Standard forFire Safety, and the like require that an excellent low heat releaseperformance and an excellent low smoke generation performance besatisfied during combustion.

Various proposals have already been made in order to enhance the flameretardancy of polycarbonate resins. For example, PTL 1 discloses a resincomposition that contains a polycarbonate resin having a branchedstructure, a graft polymer, a phosphorus flame retardant, talc, and soforth. PTL 2 and PTL 3 disclose polycarbonate resin compositions thatcontain a silicone acrylate rubber, talc, and a phosphorus flameretardant.

However, these polycarbonate resin compositions are unable to complywith the aforementioned standard, which requires higher fire protectionstandards.

CITATION LIST Patent Literature [PTL 1] Japanese Patent No. 5128480 [PTL2] Japanese Patent No. 5882062 [PTL 3] JP 2014-240492 A SUMMARY OFINVENTION Technical Problem

An object of (problem to be addressed by) the present invention is toprovide a polycarbonate resin composition that achieves an excellent lowheat release performance and an excellent low smoke generationperformance.

Solution to Problem

As a result of extensive and intensive investigations directed tosolving the indicated problem, the present inventor discovered that—byadding the combination of a phosphorus flame retardant and a siliconeflame retardant to a polycarbonate resin having a prescribed structureand additionally incorporating an inorganic filler—an excellent charformation is promoted during combustion, an excellent low heat releaseperformance and an excellent smoke generation performance can beexpressed, and the high fire protection standards as described above canbe achieved. The present invention was achieved based on this discovery.

The polycarbonate resin composition according to the first invention ofthe present invention characteristically contains 100 mass parts of apolycarbonate resin that contains a polycarbonate resin (A1) having astructural unit with the following general formula (1) and apolycarbonate resin (A2) having a structural unit with the followinggeneral formula (2), in a proportion of 100/0 to 10/90 for the (A1)/(A2)mass ratio; 3 to 20 mass parts of a phosphorus flame retardant (B); 2 to20 mass parts of a silicone flame retardant (C); and 3 to 100 mass partsof an inorganic filler (D), wherein the phosphorus flame retardant (B)is a phosphazene compound and/or a condensed phosphate ester.

In general formula (1), R¹ represents a methyl group; R² represents ahydrogen atom or a methyl group; X represents

wherein, R³ and R⁴ represent a hydrogen atom or a methyl group; and Zrepresents a group that by bonding to the carbon atom C forms a possiblysubstituted alicyclic hydrocarbon having 6 to 12 carbons.

(X in general formula (2) is defined as for general formula (1).)

The polycarbonate resin composition according to the second invention ofthe present invention characteristically contains 100 mass parts of apolycarbonate resin containing a polycarbonate resin (A1) having astructural unit with general formula (1) as given above and apolycarbonate resin (A2) having a structural unit with general formula(2) as given above, in a proportion of (less than 10)/(more than 90) to0/100 for the (A1)/(A2) mass ratio; 3 to 40 mass parts of a phosphorusflame retardant (B); 2 to 40 mass parts of a silicone flame retardant(C); and 15 to 100 mass parts of an inorganic filler (D), wherein thephosphorus flame retardant (B) is a condensed phosphate ester, and doesnot contain a phosphazene compound or contains a phosphazene compound ina content of less than 3 mass parts.

Advantageous Effects of Invention

The first invention of the present invention can thus provide apolycarbonate resin composition that achieves an excellent low heatrelease performance and an excellent low smoke generation performance,and that accrues the effect of enabling advantageous use in particularas a material for railway vehicle interiors.

The second invention of the present invention can thus also provide apolycarbonate resin composition that achieves an excellent low heatrelease performance and an excellent low smoke generation performance,and that accrues the effect of enabling advantageous use in particularas a material for railway vehicle interiors.

DESCRIPTION OF EMBODIMENTS <First Invention>

The first invention of the present invention will be described in detailin the following first.

In this Description, the constituent requirements of the presentinvention are described based on specific examples and representativeembodiments of the present invention; however, this should not beconstrued as a limitation of the present invention to or by thesespecific examples and embodiments.

Unless specifically indicated otherwise, in this Description “to” in thespecification of a numerical value range is used in the sense ofincluding the numerical values before and after the “to” that are usedas the lower limit and upper limit.

The polycarbonate resin composition according to the first inventioncharacteristically contains 100 mass parts of a polycarbonate resin thatcontains a polycarbonate resin (A1) having a structural unit with thepreceding general formula (1) and a polycarbonate resin (A2) having astructural unit with the preceding general formula (2), in a proportionof 100/0 to 10/90 for the (A1)/(A2) mass ratio; 3 to 20 mass parts of aphosphorus flame retardant (B); 2 to 20 mass parts of a silicone flameretardant (C); and 3 to 100 mass parts of an inorganic filler (D),wherein the phosphorus flame retardant (B) is a phosphazene compoundand/or a condensed phosphate ester.

[Polycarbonate Resin (A1)]

Polycarbonate resin (A1), which is used in the polycarbonate resincomposition of the first invention, is a polycarbonate resin that hasthe structural unit represented by the following general formula (1).

(In general formula (1), R¹ represents a methyl group; R² represents ahydrogen atom or a methyl group; X represents

R³ and R⁴ represent a hydrogen atom or a methyl group; and Z representsa group that by bonding to C forms a possibly substituted alicyclichydrocarbon having 6 to 12 carbons.)

With reference to general formula (1), R¹ is a methyl group; R² is ahydrogen atom or a methyl group; and in particular R² is preferably ahydrogen atom.

When X is

it is preferably an isopropylidene group, in which R³ and R⁴ are bothmethyl groups. When X is

Z, by bonding to the carbon C that is bonded to the two phenyl groups ingeneral formula (1), forms a divalent alicyclic hydrocarbon group having6 to 12 carbons, wherein this divalent alicyclic hydrocarbon group canbe exemplified by cycloalkylidene groups such as a cyclohexylidenegroup, a cycloheptylidene group, a cyclododecylidene group, anadamantylidene group, and a cyclododecylidene group. The substitutedforms can be exemplified by these groups bearing a methyl substituent oran ethyl substituent. Among the preceding, a cyclohexylidene group, amethyl-substituted cyclohexylidene group (preferably a3,3,5-trimethyl-substituted form), and a cyclododecylidene group arepreferred.

The following polycarbonate resins i) to iv) are preferred specificexamples of the polycarbonate resin (A1) in the first invention:

i) polycarbonate resin (A1) having the2,2-bis(3-methyl-4-hydroxyphenyl)propane structural unit, i.e., having astructural unit in which R¹ is a methyl group, R² is a hydrogen atom,and X (or —CR³R⁴—) is an isopropylidene group;

ii) polycarbonate resin (A1) having the2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane structural unit, i.e.,having a structural unit in which R¹ is a methyl group, R² is a methylgroup, and X is an isopropylidene group;

iii) polycarbonate resin (A1) having the2,2-bis(3-methyl-4-hydroxyphenyl)cyclohexane structural unit, i.e.,having a structural unit in which R¹ is a methyl group, R² is a hydrogenatom, and X (or —C(═Z)—) is a cyclohexylidene group; and

iv) polycarbonate resin (A1) having the2,2-bis(3-methyl-4-hydroxyphenyl)cyclodecane structural unit, i.e.,having a structural unit in which R¹ is a methyl group, R² is a hydrogenatom, and X (or —C(═Z)—) is a cyclododecylidene group.

Among the preceding, polycarbonate resins i), ii), and iii) are morepreferred; polycarbonate resins i) and iii) are still more preferred;and polycarbonate resin i) is particularly preferred.

These polycarbonate resins (A1) can be produced using the following,respectively, as the dihydroxy compound:2,2-bis(3-methyl-4-hydroxyphenyl) propane,2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane,2,2-bis(3-methyl-4-hydroxyphenyl)cyclohexane, and2,2-bis(3-methyl-4-hydroxyphenyl)cyclododecane.

The polycarbonate resin (A1) may also have carbonate structural unitsother than the structural unit with general formula (1) and, forexample, may have a structural unit with general formula (2) (i.e., astructural unit derived from bisphenol A) or may have a structural unitderived from another dihydroxy compound as described below. The amountof copolymerization of structural units other than the general formula(1) structural unit is generally not more than 60 mol % and ispreferably not more than 55 mol % or not more than 50 mol %, morepreferably not more than 40 mol %, still more preferably not more than30 mol %, particularly preferably not more than 20 mol % or not morethan 10 mol %, and most preferably among the preceding not more than 5mol %.

The polycarbonate resin (A1) and polycarbonate resin (A2) in the firstinvention are different resins, and even when the polycarbonate resin(A1) contains a bisphenol A-derived unit as a copolymerized unit, it isto be regarded as a polycarbonate resin (A1) as long as it has astructural unit represented by general formula (1). When thepolycarbonate resin (A1) contains a bisphenol A-derived carbonatestructural unit as a copolymerized unit, the bisphenol A-derivedcomponent in the polycarbonate resin (A1) is preferably less than 50 mol% and is more preferably not more than 30 mol %, still more preferablynot more than 20 mol %, even more preferably not more than 10 mol %, andparticularly preferably not more than 5 mol %.

The viscosity-average molecular weight (Mv) of the polycarbonate resin(A1) used in the first invention is not limited, but will generally be10,000 to 90,000. A good moldability accrues and a molded article havinga high mechanical strength is obtained when the viscosity-averagemolecular weight is in the indicated range. At below 10,000, the impactresistance undergoes a substantial decline and there is high potentialfor the production of defects, e.g., cracking and chipping, duringconversion into a product. The fluidity declines at above 90,000. Thepreferred lower limit for the viscosity-average molecular weight of thepolycarbonate resin (A1) is 11,000, with 12,000 being more preferred and15,000 being still more preferred. The preferred upper limit is 70,000,with 40,000 being more preferred, 35,000 being still more preferred, and31,000 being particularly preferred.

In this Description, the viscosity-average molecular weight (Mv) of thepolycarbonate resin is the value provided by measurement of theintrinsic viscosity [η] of the polycarbonate resin (sample) in methylenechloride at 20° C. using a Ubbelohde viscometer and calculation usingthe following formulas.

η_(sp)/C=[η]×(1+0.28η_(sp))

[η]=1.23×10⁻⁴×(Mv)^(0.83)

In the formulas, η_(sp) is the specific viscosity measured at 20° C. ona methylene chloride solution of the polycarbonate resin, and C is theconcentration of this methylene chloride solution. A methylene chloridesolution with a polycarbonate resin concentration of 0.6 g/dl is used.

A single species or a mixture of two or more species may be used for thepolycarbonate resin (A1), and the viscosity-average molecular weight maybe adjusted by mixing two or more species of polycarbonate resins havingdifferent viscosity-average molecular weights. In addition, asnecessary, a polycarbonate resin having a viscosity-average molecularweight outside the preferred range indicated above may be admixed andused.

[Polycarbonate Resin (A2)]

Polycarbonate resin (A2), which is used in the polycarbonate resincomposition of the first invention, is a polycarbonate resin that hasthe structural unit represented by the following general formula (2).

(X in general formula (2) is defined as for general formula (1).)

A preferred specific example of the polycarbonate structural unitrepresented by general formula (2) is 2,2-bis(4-hydroxyphenyl)propane,i.e., a bisphenol A-derived carbonate structural unit.

The polycarbonate resin (A2) may also have a carbonate structural unitother than the structural unit with general formula (2) and may have acarbonate structural unit derived from another dihydroxy compound. Thecopolymerization amount of structural units other than the structuralunit with general formula (2) is generally preferably less than 50 mol%, more preferably not more than 40 mol %, still more preferably notmore than 30 mol %, particularly preferably not more than 20 mol % ornot more than 10 mol %, and most preferably not more than 5 mol %.

The other dihydroxy compound can be exemplified by the followingaromatic dihydroxy compounds:

bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)butane,2,2-bis(4-hydroxyphenyl)pentane,2,2-bis(4-hydroxyphenyl)-4-methylpentane,1,1-bis(4-hydroxyphenyl)decane, 1,1-bis(4-hydroxyphenyl)cyclohexane,1,1-bis(4-hydroxyphenyl)-1-phenylethane,bis(4-hydroxyphenyl)phenylmethane, 1,1-bis(4-hydroxyphenyl)cyclopentane,9,9-bis(4-hydroxyphenyl)fluorene, 4,4′-dihydroxybenzophenone,4,4′-dihydroxyphenyl ether, 4,4′-dihydroxybiphenyl, and1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.

As described above, the polycarbonate resin (A2) is a different resinfrom the polycarbonate resin (A1), and a polycarbonate resin thatcontains a structural unit with general formula (1) as a copolymerizedunit is treated as a polycarbonate resin (A1).

The viscosity-average molecular weight (Mv) of the polycarbonate resin(A2) is not limited, but will generally be 10,000 to 90,000. A goodmoldability accrues and a molded article having a high mechanicalstrength is obtained when the viscosity-average molecular weight is inthe indicated range. At below 10,000, the impact resistance undergoes asubstantial decline and there is high potential for the production ofdefects, e.g., cracking and chipping, during conversion into a product.The fluidity declines at above 90,000. The preferred lower limit for theviscosity-average molecular weight of the polycarbonate resin (A2) is11,000, with 12,000 being more preferred and 15,000 being still morepreferred. The preferred upper limit is 70,000, with 40,000 being morepreferred, 35,000 being still more preferred, and 31,000 beingparticularly preferred.

The viscosity-average molecular weight (Mv) is defined as above.

The viscosity-average molecular weight of polycarbonate resin (A2) maybe adjusted by mixing two or more polycarbonate resins having differentviscosity-average molecular weights.

[Methods for Producing Polycarbonate Resins (A1) and (A2)]

There are no particular limitations on the method for producing thepolycarbonate resins (A1) and (A2) used in the first invention, and anymethod may be used. Examples here are the interfacial polymerizationmethod, melt transesterification method, pyridine method, ring-openingpolymerization of cyclic carbonate compounds, and solid-statetransesterification of a prepolymer.

Particularly advantageous methods among the preceding are specificallydescribed in the following.

Interfacial Polymerization Method

The production of polycarbonate resins (A1) and (A2) by the interfacialpolymerization method will be described first.

In the interfacial polymerization method, a dihydroxy compound asdescribed above and a carbonate precursor (preferably phosgene) arereacted in the presence of a reaction-inert organic solvent and anaqueous alkali solution generally while holding the pH at 9 or above,and the polycarbonate resin is obtained by subsequently carrying out aninterfacial polymerization in the presence of a polymerization catalyst.As necessary, the reaction system may contain a molecular weightmodifier (terminating agent) and may contain an oxidation inhibitor inorder to inhibit oxidation of the dihydroxy compound.

The reaction-inert organic solvent can be exemplified by chlorinatedhydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform,monochlorobenzene, and dichlorobenzene; and by aromatic hydrocarbonssuch as benzene, toluene, and xylene. A single organic solvent may beused or any combination of two or more organic solvents in anyproportions may be used.

The alkali compound in the aqueous alkali solution can be exemplified byalkali metal compounds such as sodium hydroxide, potassium hydroxide,lithium hydroxide, and sodium bicarbonate and by alkaline-earth metalcompounds, whereamong sodium hydroxide and potassium hydroxide arepreferred. A single alkali compound may be used or any combination oftwo or more alkali compounds in any proportions may be used.

There are no limitations on the concentration of the alkali compound inthe aqueous alkali solution, and generally 5 to 10 mass % is used inorder to control the pH in the aqueous alkali solution during thereaction to 10 to 12. In addition, for example, in order to control thepH of the aqueous phase to 10 to 12 and preferably 10 to 11 duringphosgene injection, the molar ratio between the bisphenol compound andthe alkali compound is generally 1:at least 1.9 and preferably 1:atleast 2.0 and is generally 1:not more than 3.2 and preferably 1:not morethan 2.5.

The polymerization catalyst can be exemplified by aliphatic tertiaryamines such as trimethylamine, triethylamine, tributylamine,tripropylamine, and trihexylamine; alicyclic tertiary amines such asN,N′-dimethylcyclohexylamine and N,N′-diethylcyclohexylamine; aromatictertiary amines such as N,N′-dimethylaniline and N,N′-diethylaniline;quaternary ammonium salts such as trimethylbenzylammonium chloride,tetramethylammonium chloride, and triethylbenzylammonium chloride;pyridine; guanine; and guanidine salts. A single polymerization catalystmay be used or any combination of two or more polymerization catalystsin any proportions may be used.

The molecular weight modifier can be exemplified by monohydric aromaticphenols that have a phenolic hydroxyl group; aliphatic alcohols such asmethanol and butanol; mercaptan; and phthalimide, among which thearomatic phenols are preferred.

These aromatic phenols can be specifically exemplified by alkylgroup-substituted phenols such as m-methylphenol, p-methylphenol,m-propylphenol, p-propylphenol, p-tert-butylphenol, and p-(long chainalkyl)-substituted phenol; vinyl group-containing phenols such asisopropenylphenol; epoxy group-containing phenols; and carboxylgroup-containing phenols such as o-hydroxybenzoic acid and2-methyl-6-hydroxyphenylacetic acid. A single molecular weight modifiermay be used or any combination of two or more molecular weight modifiersin any proportions may be used.

The amount of use of the molecular weight modifier, expressed per 100moles of the dihydroxy compound, is generally at least 0.5 moles and ispreferably at least 1 mole and is generally not more than 50 moles andis preferably not more than 30 moles. The heat stability and hydrolysisresistance of the polycarbonate resin composition can be enhanced byhaving the amount of use of the molecular weight modifier be in theindicated range.

The mixing sequence for the reaction substrates, reaction medium,catalyst, additives, and so forth for the reaction may be freelyselected as long as the desired polycarbonate resin is obtained, and thesequence may be freely established as appropriate. For example, whenphosgene is used as the carbonate precursor, the molecular weightmodifier may be admixed at any time from the reaction between thedihydroxy compound and the phosgene (phosgenation) up to and includingthe point at which the polymerization reaction is begun.

The reaction temperature is generally 0° C. to 40° C., and the reactiontime is generally several minutes (for example, 10 minutes) to severalhours (for example, 6 hours).

Melt Transesterification Method

The production of polycarbonate resins (A1) and (A2) by the melttransesterification method will now be described. For example, atransesterification reaction between a carbonate diester and a dihydroxycompound is carried out in the melt transesterification method.

The dihydroxy compound is as described above.

The carbonate diester, on the other hand, can be exemplified by dialkylcarbonate compounds such as dimethyl carbonate, diethyl carbonate, anddi-tert-butyl carbonate; diphenyl carbonate; and substituted diphenylcarbonates such as ditolyl carbonate. Among these, diphenyl carbonateand substituted diphenyl carbonates are preferred and diphenyl carbonateis particularly preferred. A single carbonate diester may be used or anycombination of two or more carbonate diesters in any proportions may beused.

Any ratio between the dihydroxy compound and carbonate diester may beused as long as the desired polycarbonate resin is obtained, butpreferably the carbonate diester is used in at least an equimolar amountper 1 mole of the dihydroxy compound, while the use of at least 1.01moles per 1 mole of the dihydroxy compound is more preferred. The upperlimit is generally not more than 1.30 moles. Using this range makes itpossible to adjust the amount of terminal hydroxyl group into a suitablerange.

The amount of terminal hydroxyl group in a polycarbonate resin tends toexercise a major influence on, inter alia, the heat stability,hydrolysis stability, and color. Due to this, as necessary the amount ofterminal hydroxyl group may be adjusted using any known method. With thetransesterification reaction, a polycarbonate resin having an adjustedamount of terminal hydroxyl group can be obtained in general byadjustment or control of, for example, the mixing ratio between thecarbonate diester and the dihydroxy compound and/or the depth of thevacuum during the transesterification reaction. The molecular weight ofthe obtained polycarbonate resin can also generally be adjusted by theseprocesses.

The mixing ratio is as described above when the amount of terminalhydroxyl group is adjusted by adjusting the mixing ratio between thecarbonate diester and the dihydroxy compound.

In addition, a separate admixture of a terminating agent may be carriedout during the reaction in a more aggressive adjustment method. Theterminating agent here can be exemplified by monohydric phenols,monobasic carboxylic acids, and carbonate diesters. A single terminatingagent may be used or any combination of two or more terminating agentsin any proportions may be used.

A transesterification catalyst is generally used in the production ofpolycarbonate resin by the melt transesterification method. Anytransesterification catalyst can be used. Among transesterificationcatalysts, the use of alkali metal compounds and/or alkaline-earth metalcompounds is preferred. In combination therewith, for example, a basiccompound, e.g., a basic boron compound, basic phosphorus compound, basicammonium compound, or an amine compound, may also be used on anauxiliary basis. A single transesterification catalyst may be used orany combination of two or more transesterification catalysts in anyproportions may be used.

The reaction temperature in the melt transesterification method isgenerally 100° C. to 320° C. The pressure during the reaction isgenerally a vacuum of 2 mmHg or below. The specific process may be theexecution of a melt polycondensation reaction under the indicated rangeof conditions while removing by-products, for example, a hydroxycompound.

The melt polycondensation reaction can be carried out by a batch methodor a continuous method. In the case of the batch method, the mixingsequence for the reaction substrates, reaction medium, catalyst,additives, and so forth may be freely selected as long as the desiredpolycarbonate resin is obtained, and the sequence may be freelyestablished as appropriate. The melt polycondensation reaction, however,is preferably carried out using a continuous regime based on aconsideration of the stability of the polycarbonate resin and thepolycarbonate resin composition.

A catalyst deactivator may also be used on an optional basis in the melttransesterification method. Any compound that can neutralize thetransesterification catalyst can be used as the catalyst deactivator.Examples here are sulfur-containing acidic compounds and theirderivatives. A single catalyst deactivator may be used or anycombination of two or more catalyst deactivators in any proportions maybe used.

The amount of use of the catalyst deactivator, expressed with referenceto the alkali metal or alkaline-earth metal present in thetransesterification catalyst, is generally at least 0.5 equivalents andpreferably at least 1 equivalent and is generally not more than 10equivalents and is preferably not more than 5 equivalents. In addition,with reference to the polycarbonate resin, it is generally at least 1mass-ppm and generally not more than 100 mass-ppm and preferably notmore than 20 mass-ppm.

The polycarbonate resins (A1) and (A2) preferably are a polycarbonateresin having a branched structure or contain a polycarbonate resinhaving a branched structure.

A branching agent may be used to introduce a branched structure into thepolycarbonate resin, and, for example, a compound having three or morefunctional groups, e.g., 1,1,1-tris(4-hydroxyphenyl)ethane,α,α′,α″-tris(4-hydroxyphenyl)-1,3,5-triisopropylbenzene,1-[α-methyl-α-(4′-hydroxyphenyl)ethyl]-4-[a′,a′-bis(4″-hydroxyphenyl)ethyl]benzene, phloroglucin, trimellitic acid,and isatinbis(o-cresol), can be used.

As described in JP H08-259687 A and JP H08-245782 A, a polycarbonateresin having a branched structure can be produced, without adding acrosslinking agent, by a melt transesterification method that uses anaromatic dihydroxy compound and a carbonate diester.

The polycarbonate resins (A1) and (A2) preferably are a polycarbonateresin having a branched structure or contain a polycarbonate resinhaving a branched structure, and the proportion of the polycarbonateresin having a branched structure in 100 mass % for the total ofpolycarbonate resins (A1) and (A2) is preferably 10 to 100 mass %. Whenthe branched structure is in a range at or above a certain level, anexcellent shape stability is exhibited during combustion and this isthus preferred from the standpoint of achieving a low heat release and alow smoke generation. The proportion of the polycarbonate resin having abranched structure is more preferably 20 to 100 mass %, still morepreferably 25 to 100 mass %, and particularly preferably 30 to 100 mass%.

With regard to the polycarbonate resin having a branched structure,either or both of polycarbonate resins (A1) and (A2) may be apolycarbonate resin having a branched structure, and a polycarbonateresin having a branched structure may be mixed as a portion of thepolycarbonate resin (A1) and/or as a portion of the polycarbonate resin(A2).

[Proportions for Polycarbonate Resins (A1) and (A2)]

The ratio in the first invention between the contents of thepolycarbonate resin (A1) and the polycarbonate resin (A2) ispolycarbonate resin (A1)/polycarbonate resin (A2)=100/0 to 10/90 as themass ratio between the two. By having polycarbonate resins (A1) and (A2)reside in this ratio, an excellent char formation is exhibited duringcombustion and the appearance of a low heat release and a low smokegeneration is facilitated.

Expressed as polycarbonate resin (A1)/polycarbonate resin (A2), thepreferred content ratio is 100/0 to 20/80, while 100/0 to 30/70 is morepreferred, 100/0 to 40/60 is still more preferred, and 100/0 to 50/50 isparticularly preferred.

[Phosphorus Flame Retardant (B)]

Considered per 100 mass parts of the total of the polycarbonate resins(A1) and (A2), the polycarbonate resin composition according to thefirst invention contains 3 to 20 mass parts of a phosphorus flameretardant (B) that is a phosphazene compound and/or a condensedphosphate ester and 2 to 20 mass parts of a silicone flame retardant(C). As a result of the incorporation of both this phosphorus flameretardant (B) that is a phosphazene compound and/or a condensedphosphate ester and the silicone flame retardant (C), the flameretardancy of the polycarbonate resin composition according to the firstinvention can be enhanced up to a level that can clear the previouslyreferenced European Railway Standard for Fire Safety.

A phosphazene compound and/or a condensed phosphate ester is used as thephosphorus flame retardant (B) in the first invention.

[Condensed Phosphate Ester]

The phosphate ester compound represented by the following generalformula (3) is particularly preferred for the condensed phosphate ester.

(In the formula, R¹, R², R³, and R⁴ each represent an alkyl group having1 to 6 carbons or an aryl group having 6 to 20 carbons and possiblysubstituted by an alkyl group; p, q, r, and s are each 0 or 1; k is aninteger from 1 to 5; and X¹ represents an arylene group.)

The phosphate ester compound represented by general formula (3) may be amixture of compounds in which k has different values, and k is then theaverage value for the mixture in the case of a mixture of phosphateesters in which this k is different. In the case of a mixture ofcompounds having different values of k, the average value of k ispreferably in the range from 1 to 2, more preferably from 1 to 1.5,still more preferably from 1 to 1.2, and particularly preferably from 1to 1.15.

In addition, the X¹ represents a divalent arylene group, for example, adivalent group derived from a dihydroxy compound such as resorcinol,hydroquinone, bisphenol A, 2,2′-dihydroxybiphenyl,2,3′-dihydroxybiphenyl, 2,4′-dihydroxybiphenyl, 3,3′-dihydroxybiphenyl,3,4′-dihydroxybiphenyl, 4,4′-dihydroxybiphenyl,1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene,1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene,1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene,1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene,2,6-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene. Among thepreceding, a divalent group derived from resorcinol, bisphenol A, or3,3′-dihydroxybiphenyl is particularly preferred.

p, q, r, and s in general formula (3) each represent 0 or 1 with 1 beingpreferred therebetween.

R¹, R², R³, and R⁴ each represent an alkyl group having 1 to 6 carbonsor an aryl group having 6 to 20 carbons and possibly substituted by analkyl group. This aryl group can be exemplified by a phenyl group, acresyl group, a xylyl group, an isopropylphenyl group, a butylphenylgroup, a tert-butylphenyl group, a di-tert-butylphenyl group, ap-cumylphenyl group, and so forth, with a phenyl group, a cresyl group,and a xylyl group being more preferred.

Specific examples of the condensed phosphate esters represented bygeneral formula (3) are condensed phosphate esters such as resorcinolbis(diphenyl phosphate) (RDP), resorcinol bis(dixylenyl phosphate)(RDX), bisphenol A bis(diphenyl phosphate) (BDP), biphenyl bis(diphenylphosphate), and tetraphenyl-p-phenylene diphosphate.

Besides those provided above, the phosphate ester compound of coursealso includes, e.g.,10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide,10-(2,3-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and10-(2,4-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide.

The phosphate ester compound is preferably an aromatic condensedphosphate compound.

The acid value of the condensed phosphate ester compound represented bygeneral formula (3) is preferably not more than 0.2 mg KOH/g, morepreferably not more than 0.15 mg KOH/g, still more preferably not morethan 0.1 mg KOH/g, and particularly preferably not more than 0.05 mgKOH/g. The lower limit for this acid value may be substantially 0.

A single condensed phosphate ester flame retardant (B) may be used orany combination of two or more in any ratio may be used.

[Phosphazene Compound]

The phosphazene compound is particularly preferably a phosphazenecompound represented by the following general formula (4) or (5).

Phosphazene compounds represented by general formulas (4) and (5) can beexemplified by cyclic and/or linear C₁₋₆-alkyl-C₆₋₂₀-aryloxyphosphazenessuch as phenoxyphosphazenes, (poly) tolyloxyphosphazenes (for example,o-tolyloxyphosphazene, m-tolyloxyphosphazene, p-tolyloxyphosphazene,o,m-tolyloxyphosphazene, o,p-tolyloxyphosphazene,m,p-tolyloxyphosphazene, o,m,p-tolyloxyphosphazene, and so forth) and(poly)xylyloxyphosphazenes; and cyclic and/or linearC₆₋₂₀-aryl-C₁₋₁₀-alkyl-C₆₋₂₀-aryloxyphosphazenes such as(poly)phenoxytolyloxyphosphazenes (for example,phenoxy-o-tolyloxyphosphazene, phenoxy-m-tolyloxyphosphazene,phenoxy-p-tolyloxyphosphazene, phenoxy-o,m-tolyloxyphosphazene,phenoxy-o,p-tolyloxyphosphazene, phenoxy-m,p-tolyloxyphosphazene,phenoxy-o,m,p-tolyloxyphosphazene), (poly) phenoxyxylyloxyphosphazenes,and (poly)phenoxytolyloxyxylyloxyphosphazenes.

The following are preferred among the preceding: cyclic and/or linearphenoxyphosphazene, cyclic and/or linearC₁₋₃-alkyl-C₆₋₂₀-aryloxyphosphazene, andC₆₋₂₀-aryloxy-C₁₋₃-alkyl-C₆₋₂₀-aryloxyphosphazene (for example, cyclicand/or linear tolyloxyphosphazene, cyclic and/or linearphenoxytolylphenoxyphosphazene, and so forth).

R⁵ and R⁶ in the cyclic phosphazene compound represented by generalformula (4) may be the same or different and represent an aryl group oran alkylaryl group. This aryl group and alkylaryl group can beexemplified by a phenyl group, a naphthyl group, a methylphenyl group,and a benzyl group, whereamong cyclic phenoxyphosphazenes, in which R⁵and R⁶ are phenyl groups, are particularly preferred.

Such cyclic phenoxyphosphazene compounds can be exemplified bycompounds, e.g., phenoxycyclotriphosphazene,octaphenoxycyclotetraphosphazene, and decaphenoxycyclopentaphosphazene,that are obtained by reacting ammonium chloride and phosphoruspentachloride at a temperature of 120° C. to 130° C. to obtain a mixtureof cyclic and linear chlorophosphazenes; recovering the cyclicchlorophosphazenes, e.g., hexachlorocyclotriphosphazene,octachlorocyclotetraphosphazene, and decachlorocyclopentaphosphazene;and subsequently substituting with a phenoxy group.

The t in general formula (4) represents an integer from 3 to 25,whereamong compounds in which t is an integer from 3 to 8 are preferred;a mixture of compounds having different values for t may also be used.Among the preceding, mixtures are preferred in which compounds with t=3are at least 50 mass %, compounds with t=4 are 10 to 40 mass %, and thetotal for compounds with a t of 5 or more is not more than 30 mass %.

R⁷ and R⁸ in general formula (5) may be the same or different andrepresent an aryl group or an alkylaryl group. This aryl group andalkylaryl group can be exemplified by a phenyl group, a naphthyl group,a methylphenyl group, and a benzyl group, whereamong linearphenoxyphosphazenes, in which R⁷ and R⁸ are phenyl groups, areparticularly preferred.

Such linear phenoxyphosphazene compounds are, for example, compoundsobtained by the ring-opening polymerization at a temperature of 220° C.to 250° C. of the hexachlorocyclotriphosphazene yielded by the methoddescribed above, followed by subjecting the resulting lineardichlorophosphazene having a degree of polymerization of 3 to 10,000 tosubstitution with a phenoxy group.

In addition, R⁹ represents at least one selected from a —N═P(OR⁷)₃group, a —N═P(OR⁸)₃ group, a —N═P(O)OR⁷ group, and a —N═P(O)OR⁸ group,while R¹⁰ represents at least one selected from a —P(OR⁷)₄ group, a—P(OR⁸)₄ group, a —P(O) (OR⁷)₂ group, and a —P(O) (OR⁸)₂ group.

The u in general formula (5) represents an integer from 3 to 10,000 andis preferably 3 to 1,000, more preferably 3 to 100, and still morepreferably 3 to 25.

The phosphazene compound may be a crosslinked phosphazene compoundprovided by the crosslinking of a portion of the phosphazene compound.The heat resistance is increased by the presence of such a crosslinkedstructure.

Such a crosslinked phosphazene compound can be exemplified by compoundshaving the crosslinking structure represented by the following generalformula (6), for example, compounds having a 4,4′-diphenylenegroup-crosslinked structure, e.g., compounds having a4,4′-sulfonyldiphenylene (i.e., a bisphenol S residue)-crosslinkedstructure, compounds having a 2,2-(4,4′-diphenylene)isopropylidenegroup-crosslinked structure, compounds having a 4,4′-oxydiphenylenegroup-crosslinked structure, and compounds having a 4,4′-thiodiphenylenegroup-crosslinked structure.

[In formula (6), X² is —C(CH₃)₂—, —SO₂—, —S—, or —O— and v is 0 or 1.]

The following are preferred for the crosslinked phosphazene compoundfrom the standpoint of the flame retardancy: crosslinkedphenoxyphosphazene compounds provided by the crosslinking, through acrosslinking group represented by general formula (4), of a cyclicphenoxyphosphazene compound in which R⁵ and R⁶ in general formula (4)are phenyl groups, and crosslinked phenoxyphosphazene compounds providedby the crosslinking, through a crosslinking group represented by generalformula (6), of a linear phenoxyphosphazene compound in which R⁷ and R⁸in general formula (5) are phenyl groups. More preferred are crosslinkedphenoxyphosphazene compounds provided by the crosslinking of a cyclicphenoxyphosphazene compound through a crosslinking group represented bygeneral formula (6).

The phenylene group content in the crosslinked phenoxyphosphazenecompound—with reference to the total number of phenyl and phenylenegroups in the cyclic phosphazene compound represented by general formula(4) and/or the linear phenoxyphosphazene compound represented by generalformula (5)—is generally 50% to 99.9% and preferably 70% to 90%. Thecrosslinked phenoxyphosphazene compound is particularly preferably acompound that does not have a free hydroxyl group in the molecule.

Viewed from the standpoint of the flame retardancy and mechanicalcharacteristics, the phosphazene compound is preferably at least oneselected from the group consisting of cyclic phenoxyphosphazenecompounds represented by general formula (4) and crosslinkedphenoxyphosphazene compounds provided by the crosslinking through acrosslinking group of a linear phenoxyphosphazene compound representedby general formula (5).

The content in the first invention of the phosphorus flame retardant (B)that is a condensed phosphate ester compound and/or a phosphazenecompound is, as described above, 3 to 20 mass parts per 100 mass partsof the total of the polycarbonate resins (A1) and (A2). Less than 3 massparts and more than 20 mass parts are undesirable because in the formercase the expression of a satisfactorily low heat release and asatisfactorily low smoke generation is impaired while in the latter casethe ability to withstand moist heat and the heat resistance, e.g., theheat deflection temperature and so forth, are reduced. The content ofthe phosphorus flame retardant (B) is preferably 3.5 to 20 mass partsand is more preferably 4 to 20 mass parts, still more preferably 5 to 20mass parts, even more preferably 8 to 20 mass parts, and particularlypreferably 10 to 20 mass parts. The upper limit on the content is morepreferably 18 mass parts, and thus 4 to 18 mass parts is more preferred,5 to 18 mass parts is still more preferred, 8 to 18 mass parts is evenmore preferred, and 10 to 18 mass parts is particularly preferred.

[Silicone Flame Retardant (C)]

The silicone flame retardant (C) is preferably a polyorganosiloxane.Polyorganosiloxanes having an aromatic group, e.g., a phenyl group andso forth, in the molecule are preferred for this polyorganosiloxane.Such polyorganosiloxanes can be exemplified by polydiphenylsiloxanes,polymethylphenylsiloxanes, polydimethyldiphenylsiloxanes, and phenylgroup-containing cyclic siloxanes.

In addition to the organic groups indicated above, thepolyorganosiloxane may contain a functional group, e.g., a silanolgroup, an epoxy group, an alkoxy group, a hydrosilyl (SiH) group, avinyl group, and so forth, in the molecule. Due to the presence of thesespecial functional groups, the compatibility between thepolyorganosiloxane and the polycarbonate resin is improved and/or thereactivity during combustion is enhanced, and the flame retardancy isthen raised as a result.

The silanol group content of the polyorganosiloxane is generally atleast 1 mass % and is preferably at least 2 mass %, more preferably atleast 3 mass %, and particularly preferably at least 5 mass %, and isgenerally not more than 10 mass %, preferably not more than 9 mass %,more preferably not more than 8 mass %, and particularly preferably notmore than 7.5 mass %. A high flame-retarding effect tends to begenerated by having the silanol group content be in the indicated range;in addition, the heat stability and moist heat stability of thepolycarbonate resin composition may undergo a substantial decline whenthe silanol group content is too large.

In addition to a hydroxyl group, the polyorganosiloxane may contain analkoxy group, but preferably in an amount not more than 10 mass %. Whenthe alkoxy group exceeds 10 mass %, gelation is prone to occur and adecline in the mechanical properties of the polycarbonate resincomposition may be induced.

The average molecular weight (mass-average molecular weight) of thepolyorganosiloxane is not particularly limited and may be selected asappropriate for use, but is generally at least 450 and is preferably atleast 1,000, more preferably at least 1,500, and particularly preferablyat least 1,700 and is generally not more than 300,000 and preferably notmore than 100,000, more preferably not more than 20,000, andparticularly preferably not more than 15,000. The production of apolyorganosiloxane having a mass-average molecular weight less than thelower limit on the indicated range is problematic, and the heatresistance of such a polyorganosiloxane may be drastically reduced. Inthe case of a polyorganosiloxane having a mass-average molecular weightin excess of the upper limit on the indicated range, due to a poordispersibility the flame retardancy assumes a declining trend and themechanical properties of the polycarbonate resin composition also assumea declining trend.

The mass-average molecular weight of the polyorganosiloxane is generallymeasured by gel permeation chromatography (GPC).

The silicone flame retardant (C) is also preferably a graft copolymerthat contains polyorganosiloxane. This may be a modifiedpolyorganosiloxane that contains polyorganosiloxane such as describedabove and another (co)polymer, for example, polybutyl acrylate, a butylacrylate-styrene copolymer, and so forth, as provided by graftcopolymerization. Such graft copolymers containing polyorganosiloxaneare commercially available, for example, as “Kane Ace MR-01” and “KaneAce MR-02” from the Kaneka Corporation.

A single silicone flame retardant (C) may be used by itself or a mixtureof two or more may be used.

The properties of the silicone flame retardant, i.e., solid, liquid, andso forth, are not particularly limited and may be selected asappropriate for use. However, in the case of a liquid, the preferredviscosity at 25° C. is generally at least 1 centistokes (cSt) and ispreferably at least 4 centistokes, and is generally not more than 500centistokes and is preferably not more than 100 centistokes.

The content of the silicone flame retardant (C) in the first inventionis 2 to 20 mass parts per 100 mass parts of the total of thepolycarbonate resins (A1) and (A2). Within this range, an excellent charformation is exhibited during combustion and the occurrence of a lowheat release and a low smoke generation is facilitated. The content ofthe silicone flame retardant (C) is preferably 3 to 18 mass parts, morepreferably 4 to 16 mass parts, and particularly preferably 5 to 15 massparts.

The total of the phosphorus flame retardant (B) and silicone flameretardant (C) contents, per 100 mass parts of the total of thepolycarbonate resins (A1) and (A2), is preferably 15 to 40 mass partsand more preferably 15 to 30 mass parts. Within this range, excellentchar formation occurs during combustion and in addition there is littlecombustion-induced deformation and the occurrence of a low heat releaseand a low smoke generation is facilitated. The total content of (B) and(C) is more preferably 20 to 30 mass parts.

[Inorganic Filler (D)]

The resin composition in the first invention contains an inorganicfiller (D).

The inorganic filler (D) can be specifically exemplified by glassfillers such as glass fiber (chopped strand), short glass fiber (milledfiber), glass flakes, and glass beads; carbon fillers such as carbonfiber, short carbon fiber, carbon nanotubes, and graphite; whiskers suchas potassium titanate and aluminum borate; silicate compounds such astalc, mica, wollastonite, kaolinite, xonotlite, sepiolite, attapulgite,montmorillonite, bentonite, and smectite; as well as silica, alumina,and calcium carbonate.

Among the preceding, talc, glass fiber, silica, and wollastonite arepreferred, with talc and glass fiber being more preferred and talc beingparticularly preferred.

The shape of the inorganic filler (D) may be freely selected and may be,for example, fibrous, acicular, plate-shaped, granular, irregular, andso forth.

When the shape of, e.g., the glass fiber and so forth, is fibrous, aselection from, e.g., long fiber types (roving) and short fiber types(chopped strand), can be used as the fiber. The average fiber diameteris preferably 6 to 16 μm and is more preferably 6 to 13 μm. Themechanical properties can be more effectively improved through the useof such fiber diameters. In addition, the average fiber length ispreferably 0.1 to 20 mm and is more preferably 1 to 10 mm. Thereinforcing effect may be inadequate when the average fiber length isless than 0.1 mm, while at more than 20 mm melt-kneading with thepolycarbonate resin and molding of the polycarbonate resin compositionmay be problematic.

When the shape of the inorganic filler (D) is other than fibrous, theaverage particle diameter is then preferably 0.05 to 50 μm and morepreferably 0.1 to 25 μm. When the average particle diameter is toosmall, the occurrence of an inadequate reinforcing effect is facilitatedand an excessive heat distortion may occur during combustion. When,conversely, the average particle diameter is too large, the externalappearance of the molded article is easily negatively affected and theimpact resistance may also be inadequate. The most preferred averageparticle diameter for the inorganic filler (D) is 0.2 to 15 μm andparticularly 0.3 to 10 μm.

As previously indicated, talc is most preferred for the inorganic filler(D), and the particle diameter of the talc, as the average particlediameter (D₅₀), is preferably 1 to 20 μm, more preferably 1 to 15 μm,and still more preferably 2 to 13 μm. A particle diameter of less than 1μm is undesirable for the following reasons: the inhibitory effect onthe heat distortion during combustion is reduced, and the resincomponent may be degraded due to an excessively large surface area inthe resin composition. It is undesirable for the average particlediameter to exceed 20 μm because the specific surface area in the resincomposition is then small and a char formation effect during combustioncapable of producing flame retardancy is impeded.

The particle diameter of the talc refers to the D₅₀ measured by a laserdiffraction scattering procedure (ISO 13320-1).

In order to increase the affinity with the polycarbonate resin (A) andenhance the adhesiveness therewith, the surface of the inorganic filler(D) is preferably treated with a surface treatment agent, e.g., a silanecoupling agent, or a sizing agent. The silane coupling agent can beexemplified by aminosilanes, epoxysilanes, allylsilanes, vinylsilanes,and so forth. The sizing agent can also contain components such as epoxyresins, urethane resins, acrylic resins, antistatic agents, lubricants,water repellents, and so forth.

Two or more inorganic fillers (D) may be used in combination. When twoor more species of talc are used in combination, two species, i.e., onehaving a smaller average particle diameter in the preferred particlediameter range and one having a larger average particle diameter in thepreferred particle diameter range, are more preferably used incombination. Specifically, the appearance of an advantageous balancebetween char formation during combustion and the suppression of heatdeflection is facilitated when talcs with an average particle diameterof 1 to 6 μm and an average particle diameter of 8 to 20 μm, preferablyan average particle diameter of 2 to 6 μm and an average particlediameter of 8 to 15 μm, and more preferably an average particle diameterof 3 to 6 μm and an average particle diameter of 8 to 12 μm are used incombination.

The content of the inorganic filler (D) in the first invention is 3 to100 mass parts per 100 mass parts of the total of polycarbonate resins(A1) and (A2). At less than 3 mass parts, the shape stabilizing effectduring combustion is weak and the low heat release performance and lowsmoke generation performance are inadequate. At more than 100 massparts, due to the wick effect of the inorganic filler, the emergence ofcombustion components to the surface during combustion is substantial,and as a consequence the low heat release performance and low smokegeneration performance readily become inadequate. The content of theinorganic filler (D) is preferably at least 5 mass parts, morepreferably at least 6 mass parts, and still more preferably at least 7mass parts, and is preferably not more than 80 mass parts, morepreferably not more than 70 mass parts, and still more preferably notmore than 50 mass parts. The content of the inorganic filler (D) is morepreferably 15 to 50 mass parts and is still more preferably 18 to 50mass parts, even more preferably 25 to 50 mass parts, and particularlypreferably 30 to 50 mass parts.

When the inorganic filler (D) is talc, the amount of talc is preferablylarger than normal from the standpoint of suppressing heat deflectionduring combustion, and, considered per 100 mass parts of the total ofpolycarbonate resins (A1) and (A2), the content is preferably 18 to 50mass parts, more preferably 25 to 50 mass parts, still more preferably30 to 50 mass parts, and particularly preferably 30 to 45 mass parts.

The ratio [(B)+(C)]/(D) between the total content of the phosphorusflame retardant (B) and silicone flame retardant (C) and the content ofthe inorganic filler (D) is preferably not more than 2 in the firstinvention. A content ratio in excess of 2 is undesirable because, inflame retardancy tests for, e.g., railway vehicles and aircraft, wherethe resin composition according to the present invention is used toparticular advantage, the shape stabilizing effect of the inorganicfiller (D) then becomes inadequate and substantial swelling anddeformation of the test specimen during flame retardancy testing may beproduced.

[(B)+(C)]/(D) is more preferably not more than 1.5, and its lower limitis preferably 0.5.

When, in particular, the phosphorus flame retardant (B) is a condensedphosphate ester, this content ratio is preferably not more than 1.5 andis preferably at least 0.3. When the phosphorus flame retardant (B) is aphosphazene compound, this content ratio is preferably not more than 1.5and is more preferably not more than 1.0 and is preferably at least 0.3.

[Fluoropolymer (E)]

The polycarbonate resin composition preferably contains a fluoropolymer(E) in the first invention. Through the incorporation of thefluoropolymer (E), the melt properties of the resin composition can beimproved and the suppression of dripping during combustion can beenhanced.

The fluoropolymer (E) can be exemplified by fluoroolefin polymers.Fluoroolefin polymers are generally polymers and copolymers that containa fluoroethylene structure. Specific examples are difluoroethylenepolymers, tetrafluoroethylene polymers,tetrafluoroethylene/hexafluoropropylene copolymer polymers, and soforth. Tetrafluoroethylene polymers are preferred among the preceding.This fluoroethylene resin can be a fibrillatable fluoroethylene resin.

Fibrillatable fluoroethylene polymers can be exemplified by “Teflon(registered trademark) 6J” from Du Pont-Mitsui Fluorochemicals Co.,Ltd., and “Polyflon (registered trademark) F201L”, “Polyflon (registeredtrademark) F103”, and “Polyflon (registered trademark) FA500B” fromDaikin Industries, Ltd. Commercially available water-based dispersionsof fluoroethylene polymers can be exemplified by “Teflon (registeredtrademark) 30J” and “Teflon (registered trademark) 31-JR” from DuPont-Mitsui Fluorochemicals Co., Ltd. and “Fluon (registered trademark)D-1” from Daikin Industries, Ltd. A fluoroethylene polymer having amultilayer structure and provided by the polymerization of vinyl monomermay also be used, and such fluoroethylene polymers can be exemplified bypolystyrene-fluoroethylene composites,polystyrene-acrylonitrile-fluoroethylene composites, polymethylmethacrylate-fluoroethylene composites, and polybutylmethacrylate-fluoroethylene composites and can be specificallyexemplified by “Metablen (registered trademark) A-3800” from MitsubishiRayon Co., Ltd. and “Blendex (registered trademark) 449” from GESpecialty Chemicals, Inc.

A single anti-dripping agent may be incorporated or two or more may beincorporated in any combination and any ratio.

The content of the fluoropolymer (E) in the first invention is 0.05 to 3mass parts per 100 mass parts of the total of the polycarbonate resins(A1) and (A2). When the content of the fluoropolymer (E) is less than0.05 mass parts, the flame retardancy-enhancing effect provided by thefluoropolymer (E) is prone to be inadequate. A content in excess of 3mass parts facilitates the occurrence of defects in the externalappearance of the molded article provided by molding of the resincomposition and facilitates the appearance of reductions in themechanical strength and transparency. The content of the fluoropolymer(E) is more preferably 0.05 to 1.5 mass parts, still more preferably0.08 to 1 mass parts, and particularly preferably 0.08 to 0.5 massparts.

[Organic Acid (F)]

The polycarbonate resin composition in the first invention preferablyalso contains an organic acid (F).

When, for example, a basic inorganic compound is used for the inorganicfiller (D), the organic acid (F) functions to neutralize this duringmolding of the resin composition and to improve the melt stability ofthe composition.

The organic acid (F) is preferably an organic compound that contains inits molecular structure at least one of a —SO₃H group, a —COOH group,and a —POH group, i.e., is preferably an organic sulfonic acid, organicphosphoric acid, or organic carboxylic acid, among which organicsulfonic acids and organic phosphoric acids are more preferred andorganic sulfonic acids are particularly preferred.

The following are examples of organic sulfonic acids that can bepreferably used as the organic acid (F): aromatic sulfonic acids such asbenzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid,naphthalenesulfonic acid, diisopropylnaphthalenesulfonic acid,diisobutylnaphthalenesulfonic acid, and dodecylbenzenesulfonic acid;aliphatic sulfonic acids having 8 to 18 carbons; and polymeric oroligomeric organic sulfonic acids, e.g., sulfonated polystyrene, methylacrylate-sulfonated styrene copolymers, and so forth.

The following are examples of organic sulfonate esters that can bepreferably used as the organic acid (F): methyl benzenesulfonate, ethylbenzenesulfonate, propyl benzenesulfonate, butyl benzenesulfonate, octylbenzenesulfonate, phenyl benzenesulfonate, methyl p-toluenesulfonate,ethyl p-toluenesulfonate, propyl p-toluenesulfonate, butylp-toluenesulfonate, octyl p-toluenesulfonate, phenyl p-toluenesulfonate,methyl naphthalenesulfonate, ethyl naphthalenesulfonate, propylnaphthalenesulfonate, butyl naphthalenesulfonate, 2-phenyl-2-propyldodecylbenzenesulfonate, and 2-phenyl-2-butyl dodecylbenzenesulfonate.

The organophosphate represented by the following general formula is alsoa preferred example of an organic phosphoric acid that can be preferablyused as the organic acid (F).

[C13]

O═P(OH)_(n)(OR¹)_(3-n)

(In the formula, R¹ represents an alkyl group or aryl group. nrepresents an integer with a value of 1 or 2. When n=1, the two R¹'s maybe the same as each other or may differ from one another.)

R¹ in the preceding general formula represents an alkyl group or an arylgroup. R¹ is more preferably an alkyl group having at least 1 andpreferably at least 2 carbons and generally not more than 30 andpreferably not more than 25 carbons, or an aryl group having at least 6and generally not more than 30 carbons. An alkyl group is more preferredfor R¹ than an aryl group. When two or more R¹'s are present, the R¹'smay each be the same as one another or may differ from one another.

Long-chain alkyl acid phosphate compounds in which R¹ has 8 to 30 carbonatoms are examples of preferred compounds with the general formula givenabove. Alkyl groups having 8 to 30 carbon atoms can be specificallyexemplified by an octyl group, a 2-ethylhexyl group, an isooctyl group,a nonyl group, an isononyl group, a decyl group, an isodecyl group, adodecyl group, a tridecyl group, an isotridecyl group, a tetradecylgroup, a hexadecyl group, an octadecyl group, an eicosyl group, and atriacontyl group.

The long-chain alkyl acid phosphates can be exemplified by octyl acidphosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, laurylacid phosphate, octadecyl acid phosphate, oleyl acid phosphate, behenylacid phosphate, phenyl acid phosphate, nonylphenyl acid phosphate,cyclohexyl acid phosphate, phenoxyethyl acid phosphate,alkoxypolyethylene glycol acid phosphate, bisphenol A acid phosphate,dimethyl acid phosphate, diethyl acid phosphate, dipropyl acidphosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctylacid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate,dilauryl acid phosphate, distearyl acid phosphate, diphenyl acidphosphate, and bisnonylphenyl acid phosphate.

Among the preceding, octadecyl acid phosphate is preferred and iscommercially available under the product name “ADK STAB AX-71” from theADEKA Corporation.

The content of the organic acid (F) in the first invention, expressedper 100 mass parts of the total of the polycarbonate resins (A1) and(A2), is preferably 0.05 to 1 mass parts and is more preferably 0.01 to0.5 mass parts.

[Stabilizer]

The polycarbonate resin composition preferably contains a stabilizer inthe first invention.

Phosphorus stabilizers and hindered phenolic stabilizers are preferredfor this stabilizer.

Any known phosphorus stabilizer can be used as the phosphorusstabilizer. Specific examples are the oxo acids of phosphorus, e.g.,phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, andpolyphosphoric acid; acidic pyrophosphate metal salts, e.g., sodiumacidic pyrophosphate, potassium acidic pyrophosphate, and calcium acidicpyrophosphate; salts of phosphoric acid with a Group 1 or Group 2Bmetal, e.g., potassium phosphate, sodium phosphate, cesium phosphate,and zinc phosphate; organophosphate compounds; organophosphitecompounds; and organophosphonite compounds, with organophosphitecompounds being particularly preferred.

The organophosphite compounds can be exemplified by triphenyl phosphite,tris(monononylphenyl) phosphite, tris(monononyl/dinonyl-phenyl)phosphite, tris(2,4-di-tert-butylphenyl) phosphite, monooctyl diphenylphosphite, dioctyl monophenyl phosphite, monodecyl diphenyl phosphite,didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite,tristearyl phosphite, and 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite.

These organophosphite compounds can be specifically exemplified by “ADKSTAB 1178”, “ADK STAB 2112”, and “ADK STAB HP-10” from the ADEKACorporation; “JP-351”, “JP-360”, and “JP-3CP” from Johoku Chemical Co.,Ltd.; and “Irgafos 168” from BASF.

Hindered phenolic oxidation inhibitors are examples of phenolicstabilizers. Specific examples thereof are pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydrophenyl)propionate],N,N′-hexan-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide],2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphoate,3,3′,3″,5,5′,5″-hexa-tert-butyl-α,α′,α″-(mesitylen-2,4,6-triyl)tri-p-cresol,4,6-bis(octylthiomethyl)-o-cresol,ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate],hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione,2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol,and2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenylacrylate.

Pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred among thepreceding. These phenolic oxidation inhibitors can be specificallyexemplified by “Irganox 1010” and “Irganox 1076” from BASF and “ADK STABAO-50” and “ADK STAB AO-60” from the ADEKA Corporation.

A single stabilizer may be incorporated or two or more may beincorporated in any combination and any ratio.

The content of the stabilizer in the first invention, expressed per 100mass parts of the total of polycarbonate resins (A1) and (A2), ispreferably at least 0.01 mass parts and more preferably at least 0.02mass parts and is preferably not more than 1 mass parts, more preferablynot more than 0.5 mass parts, and still more preferably not more than0.2 mass parts.

[Other Components]

Components other than the preceding may also be incorporated on anoptional basis. These additional components can be exemplified by resinsother than those described in the preceding and by various resinadditives.

The resin additives can be exemplified by flame retardants other thanthose described above, ultraviolet absorbers, mold-release agents,colorants, static inhibitors, antifogging agents, lubricants,anti-blocking agents, fluidity improvers, plasticizers, dispersingagents, and antiseptics. A single one of these resin additives may beincorporated or any combination of two or more in any proportions may beincorporated.

<Ultraviolet Absorber>

The polycarbonate resin composition preferably also contains anultraviolet absorber in the first invention. In particular, additionalenhancements in the weathering resistance are facilitated by co-use withthe aforementioned phosphorus stabilizer and/or phenolic stabilizer.

The ultraviolet absorber can be exemplified by organic ultravioletabsorbers such as benzotriazole compounds, benzophenone compounds,salicylate compounds, cyanoacrylate compounds, triazine compounds,oxanilide compounds, malonate ester compounds, and hindered aminecompounds. Among the preceding, benzotriazole ultraviolet absorbers,triazine ultraviolet absorbers, and malonate ester ultraviolet absorbersare more preferred.

In particular, it has been recognized that the improving effect for theweathering resistance is better for the polycarbonate resin (A1) thanfor the polycarbonate resin (A2) and that the color change is smaller.

The benzotriazole ultraviolet absorber can be specifically exemplifiedby 2-(2′-hydroxy-5′-methylphenyl)benzotriazole,2-[2′-hydroxy-3′,5′-bis(α,α-dimethylbenzyl)phenyl]benzotriazole,2-(2′-hydroxy-3′,5′-di-tert-butylphenyl)benzotriazole,2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzotriazole,2-(2′-hydroxy-3′,5′-di-tert-butylphenyl)-5-chlorobenzotriazole),2-(2′-hydroxy-3′,5′-di-tert-amyl)benzotriazole,2-(2′-hydroxy-5′-tert-octylphenyl)benzotriazole, and2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2-N-benzotriazol-2-yl)phenol],among which 2-(2′-hydroxy-5′-tert-octylphenyl)benzotriazole and2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2-N-benzotriazol-2-yl)phenol]are preferred and 2-(2′-hydroxy-5′-tert-octylphenyl)benzotriazole isparticularly preferred.

The triazine ultraviolet absorber can be specifically exemplified bytriazine ultraviolet absorbers such as2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine,2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine,2,4-diphenyl-6-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine,2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine,2,4-diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine,2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine,2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, and2,4-diphenyl-6-(2-hydroxy-4-butoxyethoxyphenyl)-1,3,5-triazine.

Specific examples of the malonate ester ultraviolet absorber are2-(alkylidene)malonate esters and particularly2-(1-arylalkylidene)malonate esters. These malonate ester ultravioletabsorbers can be specifically exemplified by “PR-25” from Clariant JapanK.K. and “B-CAP” from BASF.

The content of the ultraviolet absorber in the first invention,expressed per 100 mass parts of the total of polycarbonate resins (A1)and (A2), is preferably at least 0.05 mass parts and more preferably atleast 0.1 mass parts and is preferably not more than 1 mass parts, morepreferably not more than 0.6 mass parts, and still more preferably notmore than 0.4 mass parts. The improvement in the weathering resistancemay not be adequate when the content of the ultraviolet absorber is notmore than the lower limit on the indicated range, while, e.g., molddeposits and so forth are produced and mold contamination may be causedwhen the content of the ultraviolet absorber exceeds the upper limit onthe indicated range.

<Mold-Release Agent>

The polycarbonate resin composition preferably also contains amold-release agent in the first invention.

The mold-release agent can be exemplified by aliphatic carboxylic acids,fatty acid esters composed of an aliphatic carboxylic acid and alcohol,aliphatic hydrocarbon compounds having a number-average molecular weightof 200 to 15,000, and polysiloxane-type silicone oils. Fatty acid esterscomposed of an aliphatic carboxylic acid and alcohol are more preferredin particular among the preceding.

The aliphatic carboxylic acid constituting the fatty acid ester can beexemplified by saturated or unsaturated monobasic, dibasic, or tribasicaliphatic carboxylic acids. The aliphatic carboxylic acid here alsoencompasses alicyclic carboxylic acids. Among these, preferred aliphaticcarboxylic acids are monobasic or dibasic carboxylic acids having 6 to36 carbons, while saturated monobasic aliphatic carboxylic acids having6 to 36 carbons are more preferred. Specific examples of these aliphaticcarboxylic acids are palmitic acid, stearic acid, caproic acid, capricacid, lauric acid, arachidic acid, behenic acid, lignoceric acid,cerotic acid, melissic acid, montanic acid, tetratriacontanoic acid,adipic acid, and azelaic acid.

The alcohol constituting the fatty acid ester can be exemplified bysaturated or unsaturated monohydric alcohols and saturated orunsaturated polyhydric alcohols. This alcohol may bear a substituentsuch as a fluorine atom or aryl group. Monohydric or polyhydricsaturated alcohols having not more than 30 carbons are preferred amongthese alcohols, with saturated aliphatic monohydric alcohols andpolyhydric alcohols having not more than 30 carbons being morepreferred. Here, aliphatic also encompasses alicyclic compounds.Specific examples of the subject alcohols are octanol, decanol,dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethyleneglycol, glycerol, pentaerythritol, 2,2-dihydroxyperfluoropropanol,neopentylene glycol, ditrimethylolpropane, and dipentaerythritol.

The aliphatic carboxylic acid/alcohol fatty acid ester can bespecifically exemplified by beeswax (a mixture in which the majorcomponent is myristyl palmitate), stearyl stearate, behenyl behenate,stearyl behenate, glycerol monopalmitate, glycerol monostearate,glycerol distearate, glycerol tristearate, pentaerythritolmonopalmitate, pentaerythritol monostearate, pentaerythritol distearate,pentaerythritol tristearate, and pentaerythritol tetrastearate. Amongthe preceding, the use of at least one mold-release agent selected frompentaerythritol tetrastearate, stearyl stearate, and glycerolmonostearate is more preferred.

The content of the mold-release agent in the first invention, expressedper 100 mass parts of the total of polycarbonate resins (A1) and (A2),is preferably at least 0.05 mass parts and more preferably at least 0.1mass parts, while the upper limit thereon is preferably not more than 1mass parts, more preferably not more than 0.6 mass parts, and still morepreferably not more than 0.4 mass parts. The mold-release effect may beunsatisfactory when the content of the mold-release agent is not morethan the lower limit for the indicated range, while the hydrolysisresistance may be lowered and mold contamination during injectionmolding and so forth may be produced when the content of themold-release agent exceeds the upper limit for the indicated range.

[Production of Polycarbonate Resin Composition]

There are no particular limitations during production of thepolycarbonate resin composition in the first invention on the method formixing the polycarbonate resin with the various components and theaforementioned additives that are blended on an optional basis, and theknown methods for producing polycarbonate resin compositions can bebroadly applied.

In a specific example, the various components, e.g., the polycarbonateresin (A1), polycarbonate resin (A2), phosphorus flame retardant (B),silicone flame retardant (C), inorganic filler (D), and theaforementioned additives that are blended on an optional basis, arepreliminarily mixed using any of various mixers, e.g., a tumbler orHenschel mixer, followed by melt-kneading using a mixer such as aBanbury mixer, roll, Brabender, single-screw kneading extruder,twin-screw kneading extruder, or kneader.

The polycarbonate resin composition according to the present inventionmay also be produced, for example, without preliminarily blending theindividual components, or with a preliminary blending of only a portionof the components, and carrying out melt-kneading while feeding theextruder using a feeder.

For example, a portion of the components may be preliminarily blended,supplied to an extruder, and melt-kneaded to provide a resin compositionused as a masterbatch. This masterbatch is again blended with theremainder of the components followed by melt-kneading to produce thepolycarbonate resin composition according to the present invention.

In another preferred procedure, the inorganic filler is added, using aside-feed method and during kneading, to a resin component that has beenpreliminarily put through a melt-kneading procedure, followed by thetraverse of a light kneading zone and extrusion as a strand. Theextruded strand is pelletized by cooling and cutting. In particular, theapplication of such a method when the inorganic filler (D) is a fibrousfiller can suppress rupture of the fibrous inorganic filler and thusfacilitates an excellent maintenance of the mechanical properties.

The polycarbonate resin composition according to the first inventionpreferably exhibits a maximum average rate of heat emission of not morethan 120 kW/m². For the maximum average rate of heat emission, theaverage rate of heat emission is determined in accordance with ISO5660-1 using a cone calorimeter from the amount of consumed oxygen bytesting the obtained test specimen using conditions of a heaterirradiance of 50 kW/m² and the presence of ignition, and the maximumvalue (unit: kW/m²) of this average rate of heat emission is taken to bethe maximum average rate of heat emission. Smaller numerical values arepreferred for the maximum average rate of heat emission, and thepolycarbonate resin composition according to the first invention has amaximum average rate of heat emission preferably of not more than 120kW/m², more preferably not more than 115 kW/m², and still morepreferably not more than 110 kW/m².

In addition, the polycarbonate resin composition according to the firstinvention preferably has a specific optical density D_(s)(4) at 4minutes after the beginning of the test, which is an index for smokegeneration, of not more than 400 and preferably has a cumulative valueVOF₄ for the specific optical density for 4 minutes after the beginningof the test of not more than 650.

The specific optical density D_(s)(4) and cumulative value VOF₄ for thespecific optical density are tested in accordance with ISO 5659-2 usinga single chamber smoke generation tester and conditions of a heaterirradiance of 50 kW/m² and a flameless procedure to determine, asindices for smoke generation, the specific optical density D_(s)(4) at 4minutes after the beginning of the test and the cumulative value VOF₄for the specific optical density for 4 minutes after the beginning ofthe test.

The specific optical density D_(s) is calculated using the followingformula from the absorbance T measured with the optical system disposedwithin the chamber, the volume V of the chamber, the exposed area A ofthe test specimen, and the optical path length L of the measurementoptical system.

$\begin{matrix}{D_{s} = {\frac{V}{A \cdot L}{\log\left( \frac{100}{T} \right)}}} & \left\lbrack {{Math}.1} \right\rbrack\end{matrix}$

Smaller numerical values are preferred for both the specific opticaldensity D_(s)(4) and the cumulative value VOF₄ for the specific opticaldensity, and a low specific optical density D_(s)(4) and cumulativevalue VOF₄ for the specific optical density are indicative of a lowsmoke generation. The polycarbonate resin composition according to thefirst invention has a specific optical density D_(s)(4) preferably ofnot more than 400 and more preferably not more than 350 and a cumulativevalue VOF₄ for the specific optical density preferably of not more than650 and more preferably not more than 600.

The polycarbonate resin composition according to the first inventionparticularly preferably has a maximum average rate of heat emission ofnot more than 110 kW/m², a D_(s)(4) of not more than 350, and a VOF₄ ofnot more than 600.

[Polycarbonate Resin Molded Articles]

A polycarbonate resin molded article is produced using the polycarbonateresin composition according to the first invention that has beendescribed in the preceding. There are no particular limitations on themethod for molding the polycarbonate resin molded article, and, forexample, methods may be used that carry out molding using a heretoforeknown molding device, e.g., an injection molder, extrusion molder, andso forth.

Polycarbonate resin molded articles provided by molding the resincomposition according to the first invention, because they possess bothlow heat release and low smoke generation and can clear EN 45545-2European Railway Standard for Fire Safety and NFPA 130 Standard forFixed Guideway Transit and Passenger Rail Systems, are particularly wellsuited for, for example, interior members for railway vehicles.

Preferred examples of interior members for railway vehicles are seatrailings, back rests, tables, boxes, pockets, luggage racks, wallmaterials, ceiling materials, and so forth.

<Second Invention>

The second invention according to the present invention is described indetail in the following.

The polycarbonate resin composition according to the second inventioncharacteristically contains 100 mass parts of a polycarbonate resincontaining a polycarbonate resin (A1) having a structural unit withgeneral formula (1) as given above and a polycarbonate resin (A2) havinga structural unit with general formula (2) as given above, in aproportion of (less than 10)/(more than 90) to 0/100 for the (A1)/(A2)mass ratio; 3 to 40 mass parts of a phosphorus flame retardant (B); 2 to40 mass parts of a silicone flame retardant (C); and 15 to 100 massparts of an inorganic filler (D), wherein the phosphorus flame retardant(B) is a condensed phosphate ester, and does not contain a phosphazenecompound or contains a phosphazene compound in a content of less than 3mass parts.

The individual components themselves used in the polycarbonate resincomposition according to the second invention of the present inventionare substantially the same components as those described for the firstinvention of the present invention, and, unless specifically indicatedotherwise, the description for the first invention as provided above isdirectly applied to the individual components themselves used in thesecond invention.

[Proportion for Polycarbonate Resins (A1) and (A2)]

The ratio in the second invention between the contents of thepolycarbonate resin (A1) and the polycarbonate resin (A2) is apolycarbonate resin (A1)/polycarbonate resin (A2) of (less than10)/(more than 90) to 0/100 for the mass ratio between the two, i.e.,the polycarbonate resin (A1) is at least 0 and less than 10 and thepolycarbonate resin (A2) is more than 90 and not more than 100. When thepolycarbonate resins (A1) and (A2) are brought into this ratio and whenthe phosphorus flame retardant (B) is a condensed phosphate ester and aphosphazene compound is not incorporated, or, when it is incorporated,the phosphazene compound content is less than 3 mass parts per 100 massparts for the total of the polycarbonate resins (A1) and (A2), anexcellent char formation is exhibited during combustion and theappearance of a low heat release and a low smoke generation is madepossible.

[Phosphorus Flame Retardant (B)]

The polycarbonate resin composition according to the second inventionuses a condensed phosphate ester as the phosphorus flame retardant (B)and does not contain a phosphazene compound or, if it does contain aphosphazene compound, has a content thereof of less than 3 mass parts.Through the use of this condensed phosphate ester in combination withthe silicone flame retardant (C), the flame retardancy of thepolycarbonate resin composition according to the second invention can beenhanced up to a level that can clear the aforementioned EuropeanRailway Standard for Fire Safety.

The condensed phosphate ester and phosphazene compound are as describedabove.

As indicated above, the content in the second invention of thephosphorus flame retardant (B) is 3 to 40 mass parts per 100 mass partsfor the total of the polycarbonate resins (A1) and (A2), and preferablythe entire amount is a condensed phosphate ester. When a phosphazenecompound is incorporated, its content is less than 3 mass parts. Acontent of the phosphorus flame retardant (B) of less than 3 mass partsis undesirable because the expression of a satisfactory low heat releaseperformance and a satisfactory low smoke generation performance is thenimpaired, while at more than 40 mass parts the ability to withstandmoist heat and the heat resistance, e.g., the heat deflectiontemperature and so forth, are reduced. The content of the phosphorusflame retardant (B) is preferably 3.5 to 20 mass parts and is morepreferably 4 to 20 mass parts, still more preferably 5 to 20 mass parts,even more preferably 8 to 20 mass parts, and particularly preferably 10to 20 mass parts. The upper limit on the content is more preferably 18mass parts, and thus 4 to 18 mass parts is more preferred, 5 to 18 massparts is still more preferred, 8 to 18 mass parts is even morepreferred, and 10 to 18 mass parts is particularly preferred.

When a phosphazene compound is incorporated, its content is preferablyless than 2.5 mass parts, more preferably less than 2.0 mass parts, andstill more preferably less than 1.5 mass parts, whereamong less than 1.0mass parts, specifically less than 0.5 mass parts, particularly lessthan 0.3 mass parts, and less than 0.1 mass parts are most preferred.

[Silicone Flame Retardant (C)]

The silicone flame retardant (C) is as has been described above.

The content of the silicone flame retardant (C) in the second inventionis 2 to 40 mass parts with reference to 100 mass parts of the total ofthe polycarbonate resins (A1) and (A2). Within this range, an excellentchar formation is exhibited during combustion and the occurrence of alow heat release and a low smoke generation is facilitated. The contentof the silicone flame retardant (C) is preferably 3 to 18 mass parts,more preferably 4 to 16 mass parts, and particularly preferably 5 to 15mass parts.

The total of the phosphorus flame retardant (B) and silicone flameretardant (C) contents, with reference to 100 mass parts of the total ofthe polycarbonate resins (A1) and (A2), is preferably 15 to 40 massparts and more preferably 15 to 30 mass parts. Within this range, anexcellent char formation occurs during combustion and in addition thereis little combustion-induced deformation and the occurrence of a lowheat release and a low smoke generation is facilitated. The totalcontent of (B) and (C) is more preferably 20 to 30 mass parts.

[Inorganic Filler (D)]

The inorganic filler (D) is as described above.

The content of the inorganic filler (D) in the second invention is 15 to100 mass parts per 100 mass parts of the total of polycarbonate resins(A1) and (A2). At less than 15 mass parts, the shape stabilizing effectduring combustion is weak and the low heat release performance and lowsmoke generation performance are inadequate. At more than 100 massparts, due to the candle-core effect of the inorganic filler, theemergence of combustion components to the surface during combustion issubstantial, and as a consequence the low heat release performance andlow smoke generation performance readily become inadequate. The contentof the inorganic filler (D) is preferably at least 20 mass parts andmore preferably at least 25 mass parts and is preferably not more than80 mass parts, more preferably not more than 70 mass parts, and stillmore preferably not more than 50 mass parts. The content of theinorganic filler (D) is more preferably 20 to 80 mass parts and is stillmore preferably 20 to 70 mass parts, even more preferably 25 to 70 massparts, and particularly preferably 30 to 60 mass parts.

When the inorganic filler (D) is talc, the amount of talc is preferablylarger than normal, and, considered per 100 mass parts of the total ofpolycarbonate resins (A1) and (A2), is preferably 18 to 50 mass parts,more preferably 25 to 50 mass parts, still more preferably 30 to 50 massparts, and particularly preferably 30 to 45 mass parts.

The ratio [(B)+(C)]/(D) between the total content of the phosphorusflame retardant (B) and silicone flame retardant (C) and the content ofthe inorganic filler (D) is preferably not more than 2 in the secondinvention. A content ratio in excess of 2 is undesirable because, inflame retardancy tests for, e.g., railway vehicles and aircraft, theshape stabilizing effect of the inorganic filler (D) then becomesinadequate and substantial swelling and deformation of the test specimenduring flame retardancy testing may be produced.

[(B)+(C)]/(D) is more preferably not more than 1.5, its lower limit ispreferably 0.5, and 0.3 to 1.5 is particularly preferred.

[Fluoropolymer (E)]

A fluoropolymer (E) is also preferably incorporated in the secondinvention, and this fluoropolymer (E) is in accordance with thedescription given above.

The content of the fluoropolymer (E) in the second invention is 0.05 to3 mass parts per 100 mass parts of the total of the polycarbonate resins(A1) and (A2). When the content of the fluoropolymer (E) is less than0.05 mass parts, the flame retardancy-enhancing effect provided by thefluoropolymer (E) is prone to be inadequate. A content in excess of 3mass parts facilitates the appearance of defects in the externalappearance of the molded article provided by molding of the resincomposition and facilitates the appearance of reductions in themechanical strength and transparency. The content of the fluoropolymer(E) is more preferably 0.05 to 1.5 mass parts, still more preferably0.08 to 1 mass parts, and particularly preferably 0.08 to 0.5 massparts.

[Organic Acid (F)]

The polycarbonate resin composition in the second invention alsopreferably incorporates an organic acid (F), and this organic acid (F)is in accordance with the description given above.

The amount of incorporation of the organic acid (F) in the secondinvention, per 100 mass parts of the total of the polycarbonate resins(A1) and (A2), is preferably 0.05 to 1 mass parts and more preferably0.01 to 0.5 mass parts.

[Stabilizer]

The polycarbonate resin composition in the second invention alsopreferably incorporates a stabilizer, and this stabilizer is inaccordance with the description given above.

The content of the stabilizer in the second invention, expressed per 100mass parts of the total of polycarbonate resins (A1) and (A2), ispreferably at least 0.01 mass parts and more preferably at least 0.02mass parts and is preferably not more than 1 mass parts, more preferablynot more than 0.5 mass parts, and still more preferably not more than0.2 mass parts.

[Other Components]

Components other than the preceding may also be incorporated on anoptional basis in the resin composition according to the secondinvention. These additional components can be exemplified by resinsother than those described in the preceding and by various resinadditives.

The incorporation of, e.g., a polyphenylene ether resin, polyarylateresin, polyetherimide resin, polyamide resin, and so forth, as thisother resin is also preferred because this provides an additionalsuppression of heat release and smoke generation.

The polyphenylene ether resin is preferably a modified polyphenyleneether resin alloyed with, e.g., a high-impact polystyrene (HIPS). Thepolyarylate resin is a resin that contains an arylate polyesterstructural unit, this being the reaction product of a diphenol and anaromatic dicarboxylic acid, and a polymer provided by the polymerizationof bisphenol A and phthalic acid (terephthalic acid and/or isophthalicacid) is particularly preferred. The polyetherimide resin isparticularly preferably a polymer from2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane and m-phenylenediamine.

When these resins are incorporated, the content, per 100 mass parts ofthe total of polycarbonate resins (A1) and (A2), is preferably 5 to 100mass parts and is more preferably 10 to 60 mass parts. These may also beblended into the above-described resin composition according to thefirst invention, and the content in such a case is the same as indicatedhere.

These other resins may also be exemplified by thermoplastic polyesterresins, e.g., polyethylene terephthalate resins, polytrimethyleneterephthalate, and polybutylene terephthalate resins; styrenic resinssuch as polystyrene resins, high-impact polystyrene resins (HIPS), andacrylonitrile-styrene copolymers (AS resins); polyolefin resins such aspolyethylene resins and polypropylene resins; polyurethane resins;polymethacrylate resins; polyamide resins; polyimide resins;polyphenylene sulfide resins; and polysulfone resins.

A single additional resin may be incorporated or two or more may beincorporated in any combination and any ratio.

The resin additives can be exemplified by flame retardants other thanthose described above, ultraviolet absorbers, mold-release agents,colorants, static inhibitors, antifogging agents, lubricants,anti-blocking agents, fluidity improvers, plasticizers, dispersingagents, and antiseptics. A single one of these resin additives may beincorporated or any combination of two or more in any proportions may beincorporated.

The description of these resin additives and their preferred contentsfor the second invention are the same as given in the description of thefirst invention.

As with the first invention, the polycarbonate resin compositionaccording to the second invention preferably exhibits a value of notmore than 120 kW/m² for the maximum average rate of heat emission, andthe maximum average rate of heat emission is preferably not more than120 kW/m², more preferably not more than 115 kW/m², and still morepreferably not more than 110 kW/m².

In addition, as with the first invention, the polycarbonate resincomposition according to the second invention preferably has a specificoptical density D_(s)(4) of not more than 400 and a cumulative valueVOF₄ for the specific optical density of not more than 650.

The polycarbonate resin composition according to the second inventionhas a specific optical density D_(s)(4) preferably of not more than 400and more preferably not more than 350 and a cumulative value VOF₄ forthe specific optical density preferably of not more than 650 and morepreferably not more than 600.

As for the first invention, the polycarbonate resin compositionaccording to the second invention particularly preferably has a maximumaverage rate of heat emission of not more than 110 kW/m², a D_(s)(4) ofnot more than 350, and a VOF₄ of not more than 600.

[Polycarbonate Resin Molded Articles]

A polycarbonate resin molded article is produced using the polycarbonateresin composition according to the second invention that has beendescribed in the preceding. There are no particular limitations on themethod for molding the polycarbonate resin molded article, and, forexample, methods may be used that carry out molding using a heretoforeknown molding device, e.g., an injection molder, extrusion molder, andso forth.

Polycarbonate resin molded articles provided by molding the resincomposition according to the second invention, because they possess bothlow heat release and low smoke generation and can clear EN 45545-2European Railway Standard for Fire Safety and NFPA 130 Standard forFixed Guideway Transit and Passenger Rail Systems, are particularly wellsuited for, for example, interior members for railway vehicles.

Preferred examples of interior members for railway vehicles are seatrailings, back rests, tables, boxes, pockets, luggage racks, wallmaterials, ceiling materials, and so forth.

EXAMPLES Examples of First Invention

The first invention is specifically described in the following usingexamples in accordance with the first invention. However, the firstinvention should not be construed as being limited to or by thefollowing examples.

The various components used in the examples and comparative examples areas indicated in the following Table 1.

TABLE 1 component designation polycarbonate A1-1 aromatic polycarbonateresin produced by melt transesterification resin using bisphenol C as astarting material (A1) viscosity-average molecular weight Mv: 28000,pencil hardness: 2H, has branched structure A1-2 aromatic polycarbonateresin produced by interfacial polymerization using bisphenol A andbisphenol C as starting materials in a 50:50 molar ratioviscosity-average molecular weight Mv: 25000, pencil hardness: F, doesnot have a branched structure polycarbonate A2-1 aromatic polycarbonateresin produced by melt polymerization resin using bisphenol A as astarting material (A2) product name: Novarex M7028B, MitsubishiEngineering-Plastics Corporation viscosity-average molecular weight Mv:27000, pencil hardness: 2B, has branched structure A2-2 aromaticpolycarbonate resin produced by interfacial polymerization according toExample 1 (PC-1) of WO 2011/132510, using bisphenol A as a startingmaterial viscosity-average molecular weight: 64000, pencil hardness: 2B,does not have a branched structure A2-3 aromatic polycarbonate resinfrom bisphenol A starting material product name: Iupilon E-2000,Mitsubishi Engineering-Plastics Corporation viscosity-average molecularweight: 28000, pencil hardness: 2B, does not have a branched structurephosphorus B-1 phosphazene flame retardant flame phenoxyphosphazenecompound retardant product name: Rabitle FP-100, Fushimi PharmaceuticalCo., Ltd. (B) B-2 condensed phosphate ester flame retardant bisphenol Abisdiphenyl phosphate product name: Adeka Stab FP-600, ADEKA CorporationB-3 condensed phosphate ester flame retardant resorcinol (dixylenylphosphate) product name: PX-200, Daihachi Chemical Industry Co., Ltd.B-4 condensed phosphate ester flame retardant aromatic phosphate estercompound product name: FyrolFlex Sol-DP, ICL silicone C-1polydimethylsiloxane/acrylate ester graft copolymer flame product name:KaneAce MR-02, Kaneka Corporation retardant C-2 polymethylphenylsiloxane(C) product name: TSF437, Momentive C-3 polydimethylsiloxane/acrylateester graft copolymer product name: Metablen S-2030, Mitsubishi ChemicalCorporation C-4 polydimethylsiloxane/acrylate ester graft copolymerproduct name: Metablen SX-005, Mitsubishi Chemical Corporation inorganicD-1 talc filler product name: Micron White 5000S, Hayashi Kasei Co., Ltd(D) average particle diameter D₅₀ = 4.75 μm D-2 talc product name:Luzenac HAR T84, IMERYS Minerals Japan KK average particle diameter D₅₀= 10.5 μm D-3 talc, surface-reated product product name: Luzenac R7,IMERYS Minerals Japan KK average particle diameter D₅₀ = 5.7 μm D-4glass fiber product name: Chopped Strand ECS03T-571, Nippon ElectricGlass Co., Ltd. diameter = 13 μm. length = 3 mm D-5 wollastonite productname: NYGLOS8, IMERYS Minerals Japan KK average particle diameter D₅₀ =12 μm fluoropolymer E fibrillatable polytetrafluoroethylene (E) productname: Polyflon MPAFA-500H, Daikin Industries, Ltd. organic acid F-1 O =P(OH)_(n)(OC₁₈H₃₇)_(3−n) (mixture of n =1, 2) (F) product name: AdekaStab AX-71, ADEKA Corporation F-2 p-toluenesulfonic acid monohydrateWako Pure Chemical Industries, Ltd. stabilizer G phosphite heatstabilizer (G) tris(2,4-di-tert-butyphenyl) phosphite product name:Adeka Stab 2112, ADEKA Corporation

The polycarbonate resin (A1-1) used as a polycarbonate resin (A1) wasproduced by the following method.

<Production of Polycarbonate Resin (A1-1) by Melt TransesterificationMethod>

26.14 moles (6.75 kg) of 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e.,bisphenol C, “BPC” in the following) and 26.66 moles (5.71 kg) diphenylcarbonate were introduced into an SUS reactor (40 liter internalcapacity) equipped with a stirrer and distillation condenser; theinterior of the reactor was substituted with nitrogen gas; and thetemperature was then raised over 30 minutes to 220° C. in a nitrogen gasatmosphere.

Then, the reaction liquid in the reactor was stirred; cesium carbonate(Cs₂CO₃) was added to the melt reaction liquid as a transesterificationreaction catalyst to provide 1.5×10⁻⁶ mole per 1 mole of the BPC; andthe reaction liquid was stirred and matured for 30 minutes at 220° C. ina nitrogen gas atmosphere. The pressure in the reactor was reduced atthe same temperature to 100 Torr over 40 minutes and a reaction was runfor 100 minutes while distilling out the phenol.

The pressure in the reactor was then reduced to 3 Torr while raising thetemperature to 280° C. over 60 minutes and phenol was distilled out inan amount corresponding to approximately the entire stoichiometricamount. The pressure in the reactor was subsequently maintained at lessthan 1 Torr at the same temperature, and the polycondensation reactionwas finished by continuing to react for an additional 80 minutes. Duringthis time, the stirring rotation rate by the stirrer was 38 rpm; thereaction liquid temperature immediately prior to the end of the reactionwas 300° C.; and the stirring power was 1.40 kW.

While in the melt state, the reaction liquid was subsequentlytransferred to a twin-screw extruder, and the reaction liquid waskneaded while supplying, from the first supply port of the twin-screwextruder, butyl p-toluenesulfonate in an amount that was four times thatof the cesium carbonate on a molar basis. The reaction solution was thenpassed through the die of the twin-screw extruder and extruded in strandform and cut with a cutter to obtain carbonate resin pellets.

The properties of the obtained polycarbonate resin (A1-1) were asfollows:

pencil hardness: 2H, viscosity-average molecular weight (Mv): 28,000,branched structure=present.

The polycarbonate resin (A1-2) used as a polycarbonate resin (A1) is apolycarbonate resin produced by interfacial polymerization in accordancewith the method described in paragraph [0132] of JP 2013-112780 A, andhas the following properties:

pencil hardness: F, viscosity-average molecular weight (Mv): 25,000,branched structure=not present.

Examples 1 to 68 and Comparative Examples 1 to 7

The components indicated above were blended and mixed in the proportions(mass parts in all instances) given in Table 2 below and kneaded at abarrel temperature of 280° C. using a twin-screw extruder (“TEX30 XCT”,The Japan Steel Works, Ltd.) to produce polycarbonate resin compositionpellets. The obtained pellets were dried for 5 hours at 80° C., followedby test specimen fabrication according to the following procedure andevaluation as described below.

Using a J55AD injection molder from The Japan Steel Works, Ltd., theresin pellets obtained as described above were injection molded underconditions of a resin temperature of 280° C. and a mold temperature of80° C. to produce a length 100 mm×width 100 mm×thickness 3 mmplate-shaped test specimen.

[Maximum Average Rate of Heat Emission]

Using a Cone calorimeter C3 from Toyo Seiki Seisaku-sho, Ltd. andoperating in accordance with ISO 5660-1, testing was performed usingconditions of a heater irradiance of 50 kW/m² and the presence ofignition; the average rate of heat emission was calculated from theamount of oxygen consumption; and the maximum value of this average rateof heat emission was used as the maximum average rate of heat emission(unit: kW/m²). Smaller numerical values for the maximum average rate ofheat emission are preferred.

[Smoke Generation Test]

Operating in accordance with ISO 5659-2, the aforementioned testspecimen was cut to length 75 mm×width 75 mm×thickness 3 mm and thefollowing were measured as smoke generation indexes using an “M-323Series” from Fire Testing Technology, Ltd., a heater irradiance of 50kW/m², and a flameless procedure: the specific optical density D_(s)(4)at 4 minutes after the start of the test, and the cumulative value VOF₄for the specific optical density for 4 minutes after the start of thetest.

Using the values of the maximum average rate of heat emission, thespecific optical density D_(s)(4), and the cumulative value VOF₄ for thespecific optical density, an overall evaluation of the flame retardancywas made using the criteria in the following five-level scale A to E.

A: The maximum average rate of heat emission is not more than 110 kW/m²,D_(s)(4) is not more than 350, and VOF₄ is not more than 600.

B: The maximum average rate of heat emission is not more than 115 kW/m²,D_(s)(4) is not more than 400, and VOF₄ is not more than 650.

C: The maximum average rate of heat emission is not more than 120 kW/m²,D_(s)(4) is not more than 500, and VOF₄ is not more than 700.

D: The maximum average rate of heat emission is not more than 150 kW/m²,D_(s)(4) is not more than 600, and VOF₄ is not more than 1,000.

E: None of the A to D criteria are satisfied.

The results of the evaluations are given in the following Tables 2 to10.

TABLE 2 examples component designation 1 2 3 4 5 6 7 8 9 PC resin (A1)A1-1 100 75 50 15 50 15 50 100 100 PC resin (A2) A2-1 0 25 50 0 0 0 0 00 A2-2 0 0 0 85 50 0 0 0 0 A2-3 0 0 0 0 0 85 50 0 0 phosphorus B-1 11 1111 11 11 11 11 5 18 flame retardant (B) silicone flame C-1 7 7 7 7 7 7 77 7 retardant(C) C-2 0 0 0 0 0 0 0 0 0 inorganic D-1 20 20 20 20 20 2020 20 20 filler (D) D-2 0 0 0 0 0 0 0 0 0 fluoropolymer E 0.2 0.2 0.20.2 0.2 0.2 0.2 0.2 0.2 (E) organic acid F-1 0.14 0.14 0.14 0.14 0.140.14 0.14 0.14 0.14 (F) F-2 0 0 0 0 0 0 0 0 0 stabilizer (G) G 0.07 0.070.07 0.07 0.07 0.07 0.07 0.07 0.07 (A1)/(A2) mass ratio 100/0 75/2550/50 15/85 50/50 15/85 50/50 100/0 100/0 proportion of branched 100 100100 15 50 15 50 100 100 structure-bearing PC resin (mass %) [(B) +(C)]/(D) 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.6 1.25 maximum average rate 99107 106 110 109 111 108 100 101 of heat emission (kW/m²) Ds(4) 347 280330 378 352 382 354 346 323 VOF₄ 558 530 636 678 625 673 639 670 630overall evaluation A A B C B C B C B of flame retardancy

TABLE 3 examples component designation 10 11 12 13 14 15 16 17 PC resin(A1) A1-1 100 100 100 100 100 100 100 100 PC resin (A2) A2-1 0 0 0 0 0 00 0 A2-2 0 0 0 0 0 0 0 0 A2-3 0 0 0 0 0 0 0 0 phosphorus B-1 11 11 11 1111 11 11 11 flame retardant (B) silicone flame C-1 3 15 7 7 7 7 7 7retardant (C) C-2 0 0 4 0 0 0 0 0 inorganic D-1 20 20 25 10 45 20 20 20filler (D) D-2 0 0 0 0 0 0 0 0 fluoropolymer E 0.2 0.2 0.2 0.2 0.2 2 00.2 (E) organic acid F-1 0.14 0.14 0.14 0.14 0.14 0.14 0 0.14 (F) F-2 00 0 0 0 0 0 0.63 stabilizer (G) G 0.07 0.07 0.07 0.07 0.07 0.07 0.070.07 (A1)/(A2) mass ratio 100/0 100/0 100/0 100/0 100/0 100/0 100/0100/0 proportion of branched 100 100 100 100 100 100 100 100structure-bearing PC resin (mass %) [(B) + (C)]/(D) 0.7 1.3 0.88 1.8 0.40.9 0.9 0.9 maximum average rate 102 100 111 112 90 110 101 107 of heatemission (kW/m²) Ds(4) 350 310 307 435 278 385 352 398 VOF₄ 623 602 603700 572 680 633 698 overall evaluation B B B C A C B C of flameretardancy

TABLE 4 examples component designation 18 19 20 21 22 23 24 25 26 27 PCresin (A1) A1-1 100 75 50 100 75 50 100 100 100 100 PC resin (A2) A2-1 025 50 0 25 50 0 0 0 0 A2-2 0 0 0 0 0 0 0 0 0 0 A2-3 0 0 0 0 0 0 0 0 0 0phosphorus B-1 13 13 13 13 13 13 13 13 13 13 flame retardant (B)silicone flame C-1 8 8 8 16 16 16 16 16 8 8 retardant (C) C-2 0 0 0 0 00 0 0 0 0 inorganic D-1 35 35 35 35 35 35 0 20 0 0 filler (D) D-2 0 0 00 0 0 35 15 0 0 D-4 0 0 0 0 0 0 0 0 20 0 D-5 0 0 0 0 0 0 0 0 0 20fluoropolymer E 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 (E) organic acidF-1 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 (F) F-2 0 0 0 0 00 0 0 0 0 stabilizer (G) G 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.070.07 (A1)/(A2) mass ratio 100/0 75/25 50/50 100/0 75/25 50/50 100/0100/0 100/0 100/0 proportion of banched 100 100 100 100 100 100 100 100100 100 structure-bearing PC resin (mass %) [(B) + (C)]/(D) 0.60 0.600.60 0.83 0.83 0.83 0.83 0.83 1.05 1.05 maximum average rate 85 95 97 8793 95 93 96 119 117 of heat emission (kW/m²) Ds(4) 298 305 335 286 309312 295 306 425 476 VOF₄ 575 588 620 583 592 590 593 589 635 680 overallevaluation A A B A A A A A C C of flame retardancy

TABLE 5 comparative examples component designation 1 2 3 4 5 6 7 PCresin (A1) A1-1 0 0 0 100 100 100 0 PC resin (A2) A2-1 100 0 0 0 0 0 100A2-2 0 100 0 0 0 0 0 A2-3 0 0 100 0 0 0 0 phosphorus B-1 11 11 11 0 1111 13 flame retardant (B) silicone flame C-1 7 7 7 7 0 7 0 retardant (C)C-2 0 0 0 0 0 0 0 C-4 0 0 0 0 0 0 8 inorganic D-1 20 20 20 20 20 0 33filler (D) D-2 0 0 0 0 0 0 0 fluoropolymer E 0.2 0.2 0.2 0.2 0.2 0.2 0.2(E) organic acid F-1 0.14 0.14 0.14 0.14 0.14 0.14 0.14 (F) F-2 0 0 0 00 0 0 stabilizer (G) G 0.07 0.07 0.07 0.07 0.07 0.07 0.1 (A1)/(A2) massratio 0/100 0/100 0/100 100/0 100/0 0/100 100/0 proportion of branched100 0 0 100 100 100 100 structure-bearing PC resin (mass %) [(B) +(C)]/(D) 0.9 0.9 0.9 0.35 0.55 — 0.73 maximum average rate 123 120 125178 160 205 155 of heat emission (kW/m²) Ds(4) 536 530 526 702 680 726504 VOF₄ 725 795 719 1295 1198 1350 1039 overall evaluation D D D E E EE of flame retardancy

TABLE 6 examples component designation 28 29 30 31 32 33 34 PC resin(Al) A1-1 100 75 50 15 50 15 50 A1-2 0 0 0 0 0 0 0 PC resin (A2) A2-1 025 50 0 0 0 0 A2-2 0 0 0 85 50 0 0 A2-3 0 0 0 0 0 85 50 phosphorus flameB-2 0 0 0 0 0 0 0 retardant (B) B-3 13 13 13 13 13 13 13 B-4 0 0 0 0 0 00 silicone flame C-1 0 0 0 0 0 0 0 retardant (C) C-3 16 16 16 16 16 1616 C-4 0 0 0 0 0 0 0 inorganic D-1 35 35 35 35 35 35 35 filler (D) D-2 00 0 0 0 0 0 D-3 0 0 0 0 0 0 0 fluoropolymer E 0.2 0.2 0.2 0.2 0.2 0.20.2 (E) organic acid F-1 0.14 0.14 0.14 0.14 0.14 0.14 0.14 (F) F-2 0 00 0 0 0 0 stabilizer (G) G 0.07 0.07 0.07 0.07 0.07 0.07 0.07 (A1)/(A2)mass ratio 100/0 75/25 50/50 15/85 50/50 15/85 50/50 proportion ofbranched 100 100 100 15 50 15 50 structure-bearing PC resin (mass %)[(B) + (C)]/(D) 0.83 0.83 0.83 0.83 0.83 0.83 0.83 maximum average rate85 90 94 115 105 118 110 of heat emission (kW/m²) Ds(4) 276 272 292 412350 390 345 VOF₄ 395 366 412 680 607 640 673 overall evaluation A A A CB C B of flame retardancy

TABLE 7 examples component designation 35 36 37 38 39 40 41 42 43 44 4546 PC resin (A1) A1-1 100 100 100 50 50 30 30 50 50 30 30 0 A1-2 0 0 0 00 0 0 0 0 0 0 100 PC resin (A2) A2-1 0 0 0 50 0 70 70 50 50 70 70 0 A2-20 0 0 0 0 0 0 0 0 0 0 0 A2-3 0 0 0 0 50 0 0 0 0 0 0 0 phosphorus flameB-2 0 0 0 0 0 0 0 0 0 0 0 0 retardant (B) B-3 0 0 0 0 0 0 0 0 0 0 0 13B-4 6 13 13 13 13 13 13 13 13 13 13 0 silicone flame C-1 0 0 0 0 0 0 0 00 0 0 0 retardant (C) C-3 0 0 0 0 0 0 0 0 0 0 0 0 C-4 15 16 16 16 16 1616 16 16 16 16 16 inorganic D-1 32 34 28 34 34 34 0 24 0 17 0 34 filler(D) D-2 0 0 0 0 0 0 0 10 10 8 8 0 D-3 0 0 0 0 0 0 34 0 24 0 17 0fluoropolymer E 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 (E)organic acid F-1 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.140.14 (F) F-2 0 0 0 0 0 0 0 0 0 0 0 0 stabilizer (G) G 0.1 0.1 0.1 0.10.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 (A1)/(A2) mass ratio 100/0 100/0 100/050/50 50/50 30/70 30/70 50/50 50/50 30/70 30/70 100/0 proportion ofbranched 100 100 100 100 50 100 100 50 50 100 100 0 structure-bearing PCresin (mass %) [(B) + (C)]/(D) 0.67 0.86 1.00 0.86 0.85 0.85 0.85 0.850.85 1.16 1.16 0.85 maximum average rate 86 75 78 79 95 96 92 97 91 10094 119 of heat emission (kW/m²) Ds(4) 289 265 252 205 285 205 163 263251 239 201 375 VOF₄ 562 480 407 363 523 387 332 403 362 450 400 625overall evaluation A A A A A A A A A A A C of flame retardancy

TABLE 8 examples component designation 47 48 49 50 51 52 53 54 PC resin(A1) A1-1 100 100 100 100 100 100 100 100 PC resin (A2) A2-1 0 0 0 0 0 00 0 A2-2 0 0 0 0 0 0 0 0 A2-3 0 0 0 0 0 0 0 0 phosphorus flame B-2 5 1318 0 0 0 0 0 retardant (B) B-3 0 0 0 5 18 0 0 0 B-4 0 0 0 0 0 5 13 18silicone flame C-1 0 0 0 0 0 0 0 0 retardant (C) C-3 16 16 16 16 16 1616 16 C-4 0 0 0 0 0 0 0 0 inorganic D-1 35 35 35 35 35 35 35 35 filler(D) D-2 0 0 0 0 0 0 0 0 fluoropolymer E 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2(E) organic acid F-1 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 (F) F-2 0 00 0 0 0 0 0 stabilizer (G) G 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07(A1)/(A2) mass ratio 100/0 100/0 100/0 100/0 100/0 100/0 100/0 100/0proportion of branched 100 100 100 100 100 100 100 100 structure-bearingPC resin (mass %) [(B) + (C)]/(D) 0.60 0.83 0.97 0.60 0.97 0.60 0.830.97 maximum average rate 112 95 110 87 88 86 75 87 of heat emission(kW/m²) Ds(4) 329 299 318 305 280 289 265 279 VOF₄ 675 580 608 587 498562 480 512 overall evaluation C A C A A A A A of flame retardancy

TABLE 9 examples component designation 55 56 57 58 59 60 61 62 PC resin(A1) A1-1 100 100 100 100 100 100 100 100 PC resin (A2) A2-1 0 0 0 0 0 00 0 A2-2 0 0 0 0 0 0 0 0 A2-3 0 0 0 0 0 0 0 0 phosphorus flame B-2 0 0 00 0 0 0 0 retardant (B) B-3 13 13 13 13 13 13 13 13 B-4 0 0 0 0 0 0 0 0silicone flame C-1 3 8 16 0 0 0 0 0 retardant (C) C-3 13 13 13 3 8 13 1313 C-4 13 13 13 0 0 3 8 16 inorganic filler D-1 35 35 35 35 35 35 35 35(D) D-2 0 0 0 0 0 0 0 0 fluoropolymer E 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2(E) organic acid F-1 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 (F) F-2 0 00 0 0 0 0 0 stabilizer (G) G 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07(A1)/(A2) mass ratio 100/0 100/0 100/0 100/0 100/0 100/0 100/0 100/0proportion of branched 100 100 100 100 100 100 100 100 structure-bearingPC resin (mass %) [(B) + (C)]/(D) 1.20 1.34 1.57 0.46 0.60 0.83 0.971.20 maximum average rate 112 95 92 111 88 108 85 78 of heat emission(kW/m²) Ds(4) 380 287 277 345 285 308 298 253 VOF₄ 703 550 587 653 467478 347 345 overall evaluation C A A C A A A A of flame retardancy

TABLE 10 examples component designation 63 64 65 66 67 68 PC resin (A1)A1-1 100 100 100 100 100 100 PC resin (A2) A2-1 0 0 0 0 0 0 A2-2 0 0 0 00 0 A2-3 0 0 0 0 0 0 phosphorus flame B-2 0 0 0 0 0 0 retardant (B) B-313 13 13 13 13 13 B-4 0 0 0 0 0 0 silicone flame C-1 0 0 0 0 0 0retardant (C) C-3 16 16 16 16 16 16 C-4 0 0 0 0 0 0 inorganic filler D-110 20 45 0 0 20 (D) D-2 0 0 0 20 35 15 fluororesin (E) E 0.2 0.2 0.2 0.20.2 0.2 organic acid (F) F-1 0.14 0.14 0.14 0.14 0.14 0.14 F-2 0 0 0 0 00 stabilizer (G) G 0.07 0.07 0.07 0.07 0.07 0.07 (A1)/(A2) mass ratio100/0 100/0 100/0 100/0 100/0 100/0 100 100 100 100 100 100 [(B) +(C)]/(D) 2.90 1.45 0.64 1.45 0.83 0.83 maximum average rate 121 100 9892 86 88 of heat emission (kW/m²) Ds(4) 367 321 316 298 267 275 VOF₄ 780615 600 550 523 498 overall evaluation C B A A A A of flame retardancy

The results shown in Tables 2 to 10 demonstrate that an excellent lowheat release performance and an excellent low smoke generationperformance can be achieved for the first time by a polycarbonate resincomposition that satisfies all of the conditions prescribed for thefirst invention.

Examples of Second Invention

The second invention is specifically described in the following usingexamples in accordance with the second invention. However, the secondinvention should not be construed as being limited to or by thefollowing examples.

Besides the components already described above, the components newlyused in the examples and comparative examples are as given in thefollowing Table 11.

TABLE 11 component designation other resin PPE modified polyphenyleneether resin product name: Iupiace PX-100L, MitsubishiEngineering-Plastics Corporation PAR polyarylate resin product name:U-Polymer, POWDER RX, Unitika Ltd. PEI polyetherimide resin productname: ULTEM1000, SABIC Innovative Plastics

Examples 69 to 79

The components indicated above were blended and mixed in the proportions(mass parts in all instances) given in Table 11 below and kneaded at abarrel temperature of 280° C. using a twin-screw extruder (“TEX30 XCT”,The Japan Steel Works, Ltd.) to produce polycarbonate resin compositionpellets. The obtained pellets were dried for 5 hours at 80° C., followedby test specimen fabrication according to the same procedure asdescribed above and execution of the same evaluations.

TABLE 12 comparative examples example component designation 69 70 71 7273 74 75 76 77 78 79 7 PC resin (A1) A1-1 0 0 2 5 0 0 0 0 0 0 0 0 PCresin (A2) A2-1 100 100 98 95 100 100 100 100 0 100 100 100 A2-2 0 0 0 00 0 0 0 0 0 0 0 A2-3 0 0 0 0 0 0 0 0 100 0 0 0 additional resin PPE 0 00 0 0 11 0 0 0 0 10 0 other than PC resin PAR 0 0 0 0 0 0 11 0 0 0 0 0PEI 0 0 0 0 0 0 0 11 0 0 0 0 phosphorus flame B-1 0 0 0 0 0 0 0 0 0 0 013 retardant (B) B-3 0 0 0 0 0 0 0 0 0 13 13 0 B-4 6 13 13 13 13 15 1515 13 0 0 0 silicone flame C-4 15 16 16 16 16 9 9 9 16 16 8 8 retardant(C) inorganic filler D-1 32 34 34 34 28 38 38 38 34 34 35 33 (D)fluoropolymer E 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 (E)stabilizer (G) G 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1(A1)/(A2) mass ratio 0/100 0/100 2/98 5/95 0/100 0/100 0/100 0/100 0/1000/100 0/100 0/100 proportion of branched 100 100 100 100 100 100 100 1000 100 100 100 structure-bearing PC resin (mass %) [(B) + (C)]/(D) 0.660.85 0.85 0.85 1.04 0.63 0.63 0.63 0.85 0.85 0.60 0.73 maximum averagerate 130 117 112 108 122 149 137 125 121 146 150 155 of heat emission(kW/m²) Ds(4) 289 228 287 312 325 407 423 387 504 435 424 504 VOF₄ 607449 598 623 700 789 835 702 988 943 889 1039 overall evaluation D B B BD D D D D D D E of flame retardancy

The results shown in Table 12 demonstrate that an excellent low heatrelease performance and an excellent low smoke generation performancecan be achieved by a polycarbonate resin composition that satisfies allof the conditions prescribed for the second invention.

INDUSTRIAL APPLICABILITY

The polycarbonate resin composition according to the present inventionexhibits an excellent performance with regard to low heat release andlow smoke generation and because of this can be used as a molded articlein various applications and in particular is advantageous for interiormembers for railway vehicles and thus has a very high industrialapplicability.

1. A polycarbonate resin composition comprising: 100 mass parts of apolycarbonate resin comprising a polycarbonate resin (A1) having astructural unit of formula (1) and a polycarbonate resin (A2) having astructural unit of formula (2) in a mass ratio (A1)/(A2) of 100/0 to10/90; 3 to 20 mass parts of a phosphorus flame retardant (B), which isa phosphazene compound and/or a condensed phosphate ester of formula(3); 2 to 20 mass parts of a silicone flame retardant (C), which is apolyorganosiloxane-containing graft copolymer; and 3 to 100 mass partsof talc (D),

wherein in the formula (1), R¹ is a methyl group, R² is a hydrogen atom,and X is an isopropylidene group,

wherein in the formula (2), X is an isopropylidene group,

wherein in the formula (3), R¹, R², R³, and R⁴ each represent an alkylgroup having 1 to 6 carbons or an aryl group having 6 to 20 carbonswhich are optionally substituted by an alkyl group; p, q, r, and s areeach 0 or 1; k is an integer from 1 to 5; and X¹ represents an arylenegroup, wherein a ratio [(B)+(C)]/(D) between a total content of thephosphorus flame retardant (B) and the silicone flame retardant (C) andthe content of the talc (D) is not more than 1.05. 2-3. (canceled) 4.The polycarbonate resin composition according to claim 1, wherein acontent of the polycarbonate resin having a branched structure is 10 to100 mass % in 100 mass % of a total of polycarbonate resins (A1) and(A2).
 5. The polycarbonate resin composition according to claim 1,wherein a total content of the phosphorus flame retardant (B) and thesilicone flame retardant (C) is 15 to 40 mass parts per 100 mass partsof a total of polycarbonate resins (A1) and (A2). 6-8. (canceled)
 9. Thepolycarbonate resin composition according to claim 1, furthercomprising: 0.05 to 3 mass parts of a fluoropolymer (E) per 100 massparts of a total of the polycarbonate resins (A1) and (A2).
 10. Thepolycarbonate resin composition according to claim 1, furthercomprising: 0.05 to 1 mass parts of an organic acid (F) per 100 massparts of a total of the polycarbonate resins (A1) and (A2).
 11. Thepolycarbonate resin composition according to claim 1, wherein a maximumaverage rate of heat emission as tested in accordance with ISO 5660-1using conditions of a heater irradiance of 50 kW/m² and the presence ofignition is not more than 120 kW/m².
 12. The polycarbonate resincomposition according to claim 1, wherein a specific optical densityD_(s)(4) at 4 minutes after the beginning of the test as tested inaccordance with ISO 5659-2 using conditions of a heater irradiance of 50kW/m² and a flameless procedure is not more than
 400. 13. Thepolycarbonate resin composition according to claim 1, wherein acumulative value VOF₄ of the specific optical density for 4 minutesafter the beginning of the test as tested in accordance with ISO 5659-2using conditions of a heater irradiance of 50 kW/m² and a flamelessprocedure is not more than
 650. 14. The polycarbonate resin compositionaccording to claim 1, wherein a maximum average rate of heat emission astested in accordance with ISO 5660-1 using conditions of a heaterirradiance of 50 kW/m² and the presence of ignition is not more than 110kW/m², a D_(s)(4) at 4 minutes after the beginning of the test as testedin accordance with ISO 5659-2 using conditions of a heater irradiance of50 kW/m² and a flameless procedure is not more than 350, and acumulative value VOF₄ of the specific optical density for 4 minutesafter the beginning of the test as tested in accordance with ISO 5659-2using conditions of a heater irradiance of 50 kW/m² and a flamelessprocedure is not more than
 600. 15. A railway vehicle interior membercomprising the polycarbonate resin composition according to claim
 1. 16.The polycarbonate resin composition according to claim 1, wherein anamount of the talc (D) is 18 to 100 mass parts per 100 mass parts of atotal of polycarbonate resins (A1) and (A2).
 17. The polycarbonate resincomposition according to claim 1, wherein the ratio of [(B)+(C)]/(D) is0.3 or more.
 18. The polycarbonate resin composition according to claim1, wherein the ratio of [(B)+(C)]/(D) is 0.6 or more.